Secondary school chemistry teacher's current use of laboratory activities and the impact of expense on their laboratory choices

Abstract

In the United States with the Next Generation Science Standards (NGSS)'s emphasis on learning science while doing science, laboratory activities in the secondary school chemistry continues to be an important component of a strong curriculum. Laboratory equipment and consumable materials create a unique expense which chemistry teachers and schools must deal with if laboratory activities are part of the chemistry curriculum. While other barriers impacting teachers' use of laboratory activities have been researched, the impact of expense on teachers' choices is not as clear. This study sought to understand secondary school chemistry teachers' current laboratory practices and the impact expense has on their use of laboratory activities in their classroom. Using an online survey and follow-up interviews, the study found that a majority of secondary chemistry teachers surveyed use laboratory activities, though not always including scientific practices advocated by NGSS. The frequency of laboratory activities used by teachers was not statistically impacted by school type, available funds for materials, or processes to obtain funds, but was impacted by teachers' personal ideas. Interviews provided more information about the teachers using laboratory activities regularly and those not. While most teachers are using laboratory activities regularly at the current funding levels, expense, in terms of monetary and time expenses, was shown to impact the specific choice of laboratory activity. Implications for chemistry curriculum reform including the usage of laboratory activities in chemistry courses are discussed along with implications for chemistry teacher professional development.

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Laboratory activities have long been viewed as an important part of secondary science curriculum (Lumpe and Oliver, 1991; Hofstein and Lunetta, 2003; Kang and Wallace, 2004) and in the United States with the Next Generation Science Standards’ (NGSS) emphasis on learning science using the science and engineering practices (NGSS Lead States, 2013), their importance in the science curriculum continues to be valued. Research has shown numerous barriers to teachers' use of hands-on activities in the classroom, typically classified as inquiry activities or laboratory activities, including teacher beliefs (Roehrig and Luft, 2004; Crawford, 2007; Cheung, 2011; Rushton et al., 2011), teacher knowledge (Roehrig and Kruse, 2005; Van Driel et al., 2014), and available curriculum material (Roehrig et al., 2007; Laius et al., 2009). Expense is also cited by teachers as a barrier to hands-on activities (Penker and Elston, 2003; DeMeo, 2007). Research has explored many of the barriers, including teacher beliefs (Roehrig and Luft, 2004; Crawford, 2007; Cheung, 2011; Rushton et al., 2011) and teacher knowledge (Roehrig and Kruse, 2005; Van Driel et al., 2014), to better understand the barriers, how they influence the teachers' actions, and how the barriers might be reduced. Yet there is little research on how expense impacts teachers' actions and what might be done to reduce its impact. Given the nature of typical chemistry laboratory activities with appropriate chemical glassware, consumable non-household chemicals, and other laboratory equipment including appropriate safety equipment (e.g. fume hood, safety shower) (ACS, 2012), expense could be a greater barrier in a chemistry classroom than, for example, a physics classroom, which might need less consumable materials or less safety equipment. Because of the lack of research on the impact expense has on teachers' classroom choice, it is not clear how the influx of money might or might not impact teachers' use of laboratory activities in the classroom or if there are alternatives to help teachers, especially chemistry teachers, negotiate the impact of expense on their teaching practice without a funding change. While we assumed the existence of a threshold sum which would impact their teaching decisions as there is with most budgetary actions, we also assumed the relationship between laboratory activities and expense was more complicated. The purpose of this study was to better understand secondary school chemistry teachers' use of laboratory activities in their classroom and the impact expense has on their classroom choices, adding to the growing literature on the barriers teachers face when making teaching decisions in their classroom.

Background

Below, we describe and define laboratory activities and their importance in chemistry education. Then we discuss the current research on barriers teachers face when choosing to use laboratories activities. Since the focus of this study is on expenses’ impact on laboratory activities and materials are expensive, we review the research related to materials as barriers in more depth before situating this study.

Laboratory activities

For the purposes of this study, we defined ‘laboratory activities’ as ‘learning experiences in which the students interact with materials and/or with models to observe and understand the natural world’ (Hofstein and Lunetta, 2003, p. 31). Laboratory activities have been a valuable part of a chemistry or general science curriculum for decades because of a variety of skills and content offered in these learning opportunities (Lumpe and Oliver, 1991; Hofstein and Lunetta, 2003; Kang and Wallace, 2004). For example, laboratory activities provide students with authentic experiences, which, when structured properly, improve their learning (Hofstein et al., 2013). They help students with conceptual knowledge, skill development and problem-solving, nature of science understandings, and/or interest and motivation for learning science (Lunetta et al., 2007). NGSS once again emphasizes the need for laboratory opportunities for students in science curriculums; teachers are encouraged to engage students in the eight Science and Engineering practices (SEPs) while learning science content, or the disciplinary core ideas (NGSS Lead States, 2013). The SEPs include, among other skills, asking questions, designing and performing experiments, and analyzing data. A curriculum that includes laboratory activities has the opportunity to engage students in the SEPs.

The instructor-created scaffolding and structure of the laboratory activities determines which, if any, of the positive learning outcomes associated with laboratory activities occur (Lunetta et al., 2007; Högström et al., 2010; Hofstein et al., 2013). Laboratory activities can be designed as an inquiry activity (NRC, 2000), allowing students to learn science content while engaged is science practices including collecting and analyzing data and drawing conclusions from the data. However, inquiry activities and laboratory activities are not synonymous. For example, the POGIL curriculum (Moog et al., 2009) engages chemistry students in guided-inquiry activities outside a laboratory settings. Students are given data or models to analyze. While engaging in some of the SEPs, this type of activity does not allow students to engage in the practices of collecting data, asking questions, or carrying out experiments. Conversely, students could perform a laboratory activity which requires little critical thinking on the part of the students; typically referred to as ‘cookbook’ experiments, these laboratory activities have students collect data and carry out a directed experiment, but do not provide students with many decision-making or analytical thinking opportunities (Hofstein and Lunetta, 2003). While the structure of the laboratory activities is important to student learning (Lunetta, 2007; Högström et al., 2010; Hofstein et al., 2013), if the laboratory activities are not occurring at all they cannot impact the students’ learning. In addition, given the numerous levels of inquiry described in the literature from open-inquiry to structured or guided inquiry different people define the term inquiry differently which creates confusion with the term (Trautmann et al., 2004). As such our definition of ‘laboratory activities’ as ‘learning experiences in which the students interact with materials and/or with models to observe and understand the natural world’ (Hofstein and Lunetta, 2003, p. 31) allowed us to emphasize the need for students to interact with the materials without a teaching method connotations (i.e. the levels of inquiry or even project-based learning), but a demonstration in which only the teacher interacts with the laboratory equipment is not considered a laboratory activity. This definition also allowed us to ask questions about the characteristics of the ‘hands on’ laboratory activities to gauge the types of SEPs students are engaged in.

Barriers to implementing laboratory activities

Numerous factors have been identified as reasons teachers do not use inquiry activities or laboratory activities in their teaching. As previously mentioned laboratory activity and inquiry are not synonymous, but because inquiry activities often require materials for students to collect data to analyze (NRC, 2000), for the purposes of this review research relating to barriers for both inquiry and laboratory activities are combined in the discussion below.

Teachers' beliefs and knowledge about teaching and learning science are significant factors that influence their use of inquiry in the classroom (McDonald and Songer, 2008; Roehrig and Kruse, 2005). For example, a teacher's beliefs about how science is practiced, their Nature of Science understanding, has been shown to influence their use of inquiry in their classes (Crawford, 2007). Teachers' beliefs about how students learn impact their choices in the classroom including whether they chose to use inquiry experiments or instructional choices for student engagement and actions while implementing the experiments (Roehrig and Luft, 2004). Beliefs about their school culture or the educational system can limit the use of inquiry activities in the classroom even when personal beliefs about learning support its uses (Kang and Wallace, 2004). Content knowledge and pedagogical content knowledge have also been shown to influence the teachers' choices in their classroom (Abell, 2008). Along with their epistemological beliefs and knowledge, teachers' beliefs in themselves, their self-efficacy, has been shown to be a barrier to their use of inquiry and laboratory activities (Feyzioglu et al., 2011). These barriers are factors identified and defined by the researchers, but some studies have also asked teachers' explicitly about what prevents them from using inquiry or laboratory experiments in their classes. Teachers have self-reported several other factors that impact their teaching choices including class time (Deters, 2005; Cheung, 2008), student attitudes or resistance (Cheung, 2011), and standardized tests (Trautmann et al., 2004).

Materials as a barrier

The availability of materials has also been reported by researchers (Roehrig et al., 2007) and teachers (Cheung, 2008; Ramnarain, 2016) as a barrier to inquiry or laboratory activity use in the classroom. In the United States, Inquiry and the National Science Education Standards identified ‘availability of instructional materials, kits, and equipment’ as a support teachers need to successfully incorporate inquiry activities in their classroom. The support involves helping teachers access curriculum materials that ‘have inquiry built in’ and making sure teachers have access to ‘appropriate kits, equipment, and supplies, and that consumable supplies are replaced regularly’ (NRC, 2000, pp. 148–149). There are two different types of material availability problems; one involves curriculum materials that already include inquiry activities, i.e. laboratory activities written for students in an inquiry format, and the other involves the materials to do the activities, the ‘stuff’ for the students to use in the activities. Teachers in interviews and surveys have identified both types of material availability issues as barriers to their use of inquiry and laboratory activities in the classroom (Cheung, 2008; Ramnarain, 2016). Researchers, however, have focused primarily on the availability of and access to curricular materials on teachers' instructional practice, showing that increased access to materials with training does increase the teachers' use of inquiry in the classroom (Roehrig et al., 2007). There is much less research on the impact of the other material availability issue, the equipment and supplies, on teachers' use of inquiry and laboratory activities. A recent survey of science teachers in the US (Smith, 2013) indicated that a majority (58% and higher) of science teachers consider their supplies, including equipment, classrooms, and consumables, as adequate and for chemistry teachers the percentage was higher (71% and higher). While the teachers indicated adequate supplies, the survey did not explore how the supplies influenced their teaching choices. It is not clear from the research literature how the availability of more or different supplies influences teachers' use of inquiry or laboratory activities in their classroom. Is the impact similar to or different from the availability of curriculum materials? It is important to understand the influence of supplies on teachers' choices to include laboratory activities, not only because it is a valued instructional technique, but also because from a financial perspective there is a cost difference between the two material availability issues. Inquiry-included curriculum materials, which are typically print-based materials, could be a smaller cost for schools and teachers because they could just be purchased for teachers rather than for all students or could be reused yearly, whereas supplies for the classroom, especially consumables, can be repeated costs and more expensive if it is laboratory or safety equipment. In addition, the expense of the two different availability problems might be in terms of teachers' time rather than just monetary costs. Finding time to go through the process to purchase consumables yearly might also be an expense restricting the availability of laboratory activities. Classroom time in the curriculum is often cited by teachers as a barrier to the use of laboratory activities (Cheung, 2011; Trautmann et al., 2004), but not in terms of availability of supplies, as in an expense of their time.

Summary

Laboratory activities are an important part of the secondary school chemistry curriculum, critical to student learning and achieving chemical and scientific literacy (Hofstein and Lunetta, 2003; ACS, 2012; NGSS Lead States, 2013). And while just engaging in laboratory activities is important to learning, the structure and characteristics of the laboratory activities determine student learning as well (Lunetta, 2007; Högström et al., 2010; Hofstein et al., 2013). While numerous factors influence teachers' instructional choices, teachers have also reported that the availability of materials for the activities impact their use of laboratory or inquiry activities. But how the availability of materials based on the monetary and time expense to obtain the materials changes their teaching practices is not clear from the research literature. A better understanding of the impact of material funding on teachers' instructional choices will help continue to find solutions to improve teachers' instructional practices with the incorporation of inquiry and laboratory activities. The purpose of this study was to understand the impact of the expense of supplies, and thus the availability of those supplies, on chemistry teachers' use of laboratory activities in their classroom. Part of understanding this impact includes understanding what laboratory activities the teachers are choosing to do and the characteristics of those activities. Two research questions guided the study: (1) What are the characteristic and frequencies of the laboratory activities secondary school chemistry teachers choose and use in their teaching practices? and (2) How does the expense of laboratory-based activities impact secondary school chemistry teachers' instructional choices and classroom practices?

Methods

Due to the nature of the research questions, this study used a mixed-methods approach (Creswell, 2015), collecting quantitative and qualitative data through an online survey and individual interviews with a smaller convenience sample of the survey participants. Institutional Review Board (IRB) approval from our university was obtained for this study. Through Qualtrics, an online survey software, an approximately 10 minute survey was emailed to chemistry teachers in the state of Iowa asking them about their use of laboratory activities in their classroom along with their material and material funds availability. While classroom observations are more reliable than self-reported data about teachers' classroom practices, the survey allowed for a larger sample size. A convenience sample of fifteen teachers who completed the survey were then individually interviewed and asked to expand upon the questions from the survey. This mixed-methods approach (Creswell, 2015) provided an extended view of the chemistry teachers' classroom choices and practices that quantitative data alone would not have allowed.

Survey instrument

The survey instrument included multiple choice, Likert-scale type questions, check all that apply, and open-ended questions. Along with demographic questions about the chemistry teachers and their schools, the survey instrument (see Appendix A) included questions about the laboratory activities they used in their chemistry class and factors that might affect their choice of laboratory activities. Based on the discussion of the definition of laboratory activity above, participants were provided with the following statement before any questions about laboratory activities on the survey:

For the purpose of this study, laboratory-based activities will be defined as ‘learning experiences in which students interact with materials and/or with models to observe and understand the natural world.’ Therefore the following are NOT examples of laboratory-based activities: computer simulations, teacher demonstrations, filmed experiments, analysis of provided data, simulated lab experiments.

The survey also included questions about material availability and purchasing for their class and/or school. For all multiple choice or check all questions on the survey, ‘other’ was an option for teachers to choose and fill in. To improve the validity of the survey, four science educators and two secondary science teachers piloted a draft of the survey and provided feedback on the instrument. Based on the feedback, minor changes were made to improve the clarity and content of the questions prior to sending the survey to possible participants. A drawing for gift certificates was offered to encourage participation in the survey.

Interviews

Teachers who completed the online survey were asked if they would be willing to participate in a short follow-up phone interview. The second author was able to interview fifteen teachers using a semi-structured protocol; it was a convenience sample of teachers willing and able to be interviewed. Interviews lasted approximately 15 minutes and consisted of questions from the survey without the choices (See Appendix B for the interview protocol) and with follow-up questions to ask the teachers to provide specific examples from their classes or schools to support their answers. Interviews were arranged with the teachers immediately upon closure of the online survey in hopes to continue to get as many volunteers as possible, so very little analysis of the survey data had occurred including the formation of the groups described below.

Participants

A name-only list of 440 teachers in Iowa public schools endorsed to teach chemistry was obtained from the State of Iowa. Using internet searches of school websites for the teachers' email addresses, 414 Iowa secondary school chemistry teachers received a direct email inviting them to participate in the survey. 138 teachers (N = 138) completed the survey – a response rate of 33.3%. The participants taught at least one chemistry course at any level, i.e. introductory chemistry, honors chemistry, and/or Advanced Placement chemistry. The teachers were 44.9% male, 54.3% female, and 0.7% chose not to identify. On average, participants had 17 years of teaching experience and 14 years of experience teaching chemistry. 56% of the teachers had a Master's degree or higher. 66.7% of teachers indicated they taught at rural schools, 18.8% at suburban schools, and 14.5% at urban schools. The State of Iowa did not have statistics on teachers by discipline or even secondary science teachers generally so it is unclear if this was a representative sample of the chemistry teachers in the state based on these demographics. However, in terms of the demographics of secondary chemistry teachers from the United States, these numbers are fairly representative. A national survey reported that 54% of secondary chemistry teachers are female and 51% have taught for 11 or more years (Smith, 2013). The other demographics were not reported by this study.

To compare responses to survey questions from teachers who frequently incorporate laboratory-based activities with those not implementing them as frequently, the participants were divided into two groups to allow for analysis related to the costs and implementation of laboratory-based activities. Table 1 provides the participants’ reported use of laboratory activities in their chemistry classes.

Table 1 Frequency of laboratory-based activities in the classroom

Frequency	Number of responses (N = 138)	Percent (%)
Note. Teachers had to choose one of the above 4 choices when indicating how often they used laboratory-based activities.
0 times per month	2	1.4
1–2 times per month	30	21.7
3–5 times per month	56	40.6
More than 5 times per month	50	36.2

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According to The College Board, an Advanced Placement Chemistry course ‘requires that 25 percent of the instructional time engages students in lab investigations’ (2017, p. 1). Given this requirement for advanced chemistry courses, a roughly equal number of investigations should be expected in a course preparing students to take an advance course. Assuming a 180 day school year, 45 days of laboratory activities would be 25%, divided over 9 months, this is about 5 laboratory activities per month, or in terms of our question structure 3–5 times per month. Thus, teachers who reported ‘0 times per month’ or ‘1–2 times per month’ were placed in a ‘low frequency laboratory-based activity’ (LFLA) group (N = 32). Teachers who reported ‘3–5 times per month’ or ‘More than 5 times per month’ were placed in a ‘high frequency laboratory-based activity’ (HFLA) group (N = 106). A statistical comparison (one-way ANOVA or Chi square for categorical data) of the demographics of these two group did not produce any statistically significant difference between them (see Table 2), except in years of experience which the HFLA group had more years of experience, but the LFLA was still highly experienced with 14 years of experience on average. The LFLA group was not a group of novice teachers.

Table 2 Demographics of lab frequency groups

	LFLA (N = 32)	HFLA (N = 106)		p
Years teaching experience	Mean: 13.91 S.D.: 8.985	Mean: 18.09 S.D.: 10.557	F = 4.127	0.044
Gender	56.3% Female 43.7% Male	41.6% Female 58.4% Male	χ ^2 = 2.352	0.309
% With a Masters’ Degree	40.6%	53.8%	χ ^2 = 3.884	0.143
Teaching at rural (self-identified)	78.1%	63.2%	χ ^2 = 3.002	0.223
Teaching at grades 9–12 or 10–12 school	65.6%	79.2%	χ ^2 = 5.251	0.072

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Data analysis

Statistical analysis of the quantitative data from the survey was performed using the program IBM SPSS. Along with recording descriptive statistics for the sample, Pearson chi-square tests and one-way ANOVA tests (Field, 2013) were conducted to determine areas of difference for the lab-frequency groups as well as explore if there were differences between other groups of teachers based on demographics, which there were not. Our Likert-scale type questions required chi-square analysis rather than ANOVA because the choices were categorized i.e. never, often, always etc. (Field, 2013). An alpha level less than 0.05 (p < 0.05) was used for all tests.

The interviews were audio-recorded and transcribed using pseudonyms. A constant comparative method (Maykut and Morehouse, 1994) was used by the first author to code the transcripts. After the first round of coding, the initial codes relating to reasons teachers gave were classified into one of six final coding categories: (1) chemicals and “cheap” equipment (e.g. beakers), (2) large ‘expensive’ equipment (e.g. spectrophotometer), (3) class time, (4) personal/preparation time, (5) safety concerns, and (6) pedagogy. The transcripts were then recoded to these final categories. After coding all the transcripts, the transcripts were classified by whether they were LFLA or HFLA because the purpose of the interviews was to help understand the survey data. Similarities and differences between the codes for the sets of teachers were then explored. Only two teachers interviewed were in the LFLA group as the interviews depended on volunteers. In addition, the interviews occurred prior to full analysis of the survey data to get the volunteers while they were still willing, so there was no opportunity to increase the LFLA pool.

Results

Laboratory activities in secondary school chemistry

As Table 1 above indicates, 76.8% of chemistry teachers in Iowa are doing laboratory activities 3 or more times per month – about once a week or more. Table 3 shows how the teachers described their typical laboratory-based activities.

Table 3 Responses to “Please rate each statement to describe a typical laboratory-based activity in your classroom”

Statement	Mean^a N = 138	SD
a Means based on a scale of 1 (Does not apply), 2 (Rarely Applies), 3 (Sometimes applies), 4 (Often Applies), 5 (Always applies).
Students make observations	4.77	0.445
Students are required to wear safety equipment (e.g. pants, closed-toed shoes, goggles)	4.44	0.753
Students take measurements	4.39	0.572
Students answer post-lab questions	4.37	0.697
Students are required to support conclusions with evidence	4.26	0.757
Students work with laboratory equipment (e.g. beakers, flasks, heating devices)	4.23	0.725
Students discuss findings as a class	3.96	0.826
Students work with chemicals (e.g. NaOH, water)	3.92	0.761
Students make predictions	3.85	0.751
Students follow a given set of instructions	3.61	0.867
Students are provided with research questions	3.16	0.757
Students create a procedure	3.00	0.815
Students generate research questions	2.91	0.796

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As can be seen from Table 3 where a higher mean indicates more often, when secondary chemistry students are engaging in laboratory activities they are using equipment and chemicals traditionally associated with chemistry laboratory experiments. They are taking measurements and observations, and doing some level of post-lab analysis. Three or more times per month students are using laboratory equipment and chemicals to perform activities in which they observe and/or measure. Unfortunately the results also indicate that the labs chemistry students engage in might be rather traditional and not include many of the scientific practices advocated in NGSS. For example, following a given set of instructions had a mean score of 3.61 whereas generating a research question, Practice 1 from NGSS (NGSS Lead States, 2013), had a mean score of 2.91. Students were given a set of instructions for the laboratory activity (M = 3.61) more often than they developed their own procedure (Mean = 3.00) which is Practice 3 from NGSS. Students are engaged in laboratory activities often, but not in some of the SEPs advocated for in many reform documents like NGSS; the teachers' responses to these questions indicated they had students do laboratory activities requiring these skills sometimes (3), but not often (4).

To get teachers thinking about the barriers, any barriers, that get in their way when they want to do laboratory activities, they were asked what they do when faced with a barrier to a laboratory activity. Table 4 provides the results for this question.

Table 4 Responses to “If or when you are not able to use a laboratory-based activity, what do you do?”

Choice	Mean^a	SD
a Based on a scale of 1 (Never), 2 (Rarely), 3 (Sometimes), 4 (Often), 5 (Always). Not all teachers responded to all questions though they were prompted for an answer to each.
Alternative activity (N = 132)	3.23	0.747
Alternative laboratory-based activity (N = 137)	3.12	0.796
Skip laboratory-based activity completely (N = 136)	2.49	0.869
Lecture or discuss what would have gone on in the laboratory-based activity (N = 138)	2.43	0.951
Delay laboratory-based activity (N = 136)	1.65	0.778

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With the ability to rate each possible choice along with an ‘other’ choice and textbox, the surveyed teachers reported they sometimes find a different laboratory activity (M = 3.23) to do or an alternative activity that is not laboratory-based (M = 3.12); these responses had the highest means of the choices on a five-point scale. Skipping the activities completely or lecturing were not chosen as often. The ‘other’ choice was used by less than 1% of the teachers. Thus the 3 or more times per month of laboratory activities reported by the teachers are chosen because they are laboratory activities.

Reported impact of materials on choices

With the teachers thinking about the barriers to doing laboratory activities from the previous question, they were asked why they chose to do non-laboratory activities like computer simulations, teacher demonstrations, or virtual experiments (these examples were given to the teachers on the survey, see Appendix A for the complete survey). Table 5 provides their responses.

Table 5 Reasons for implementing non-laboratory-based activities

Reason	% Teachers selected (N = 138)
Note. Teachers could select as many choices as they wanted. There was also an ‘other’ choice with a textbox but less than 5% of the teachers chose this option.
I use them because they are supplement to my other classroom activities and lessons.	87.14
I use them because they require fewer materials.	45.71
I use them because they save time.	41.43
I use them because there are no safety restrictions.	40.00
I use them because they are equally or more valuable for student learning.	34.29
I use them because it is easier to access necessary materials.	33.57
I use them because they save money.	30.71
I use them because I prefer them.	6.43

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The chemistry teachers reported they do non-laboratory activities for pedagogical reasons, as supplements for learning. The teachers could choose as many reasons as they wanted. They did not indicate they made choices for these activities for expense reasons. However, there were teachers (less than 50%) that chose these non-laboratory activities for material or monetary reasons, indicating some level of impact of money and materials on teachers' choices.

To get a clearer picture of the impact materials might have on teachers' choices, they were provided a list of different types of resources (material and time resources) and asked about the impact of each on their choice ‘to implement a laboratory activity;’ see Table 6.

Table 6 Responses to “To what extent do you believe the following factors affect your choice to implement laboratory-based activities in your classroom?”

Factor	Mean^a N = 138	SD
Note. ‘Other’ with a textbox was also an option, but less than 5% of the teachers used this option.a Based on a scale of 1 (Does not impact my decision), 2 (Rarely impacts my decision), 3 (Often impacts my decision), 4 (Almost always impacts my decision)
Available chemicals or substances	2.86	0.873
Instrumental equipment (e.g. probes, spectrometers, analytic balances)	2.84	0.862
Class time	2.77	0.936
Funds for materials	2.56	0.915
Available procedural instructions	2.54	0.820
Necessary preparation time	2.54	0.905
Safety equipment	2.43	1.006
Technology (e.g. LoggerPro, Excel, computer applications)	2.29	0.965
Laboratory space	2.19	0.991
Laboratory equipment (e.g. beakers, graduated cylinders)	2.14	0.982
Available safety warnings	2.02	1.007
Funds for waste removal	1.94	0.815
Available materials that can be borrowed	1.81	0.737
Comfort in laboratory setting	1.80	0.902

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Of the choices provided, the availability of chemicals and instrumentation was identified by the chemistry teachers as impacting their decision the most. On a 1–4 scale, with 3 being “often impacts,” even the factors with the highest mean scores did not reach above a 3. However materials, their costs, and specialized equipment along with time did have means greater than 2.5; they are affecting the teachers' choices more than ‘rarely’ – a 2 on the scale. Fortunately, factors with lower mean scores included their classroom set ups, the space and basic equipment, and safety resources. This suggests that the material they have in school environments are rarely a barrier to their choices.

To support their response to the question from Table 6, the teachers were asked directly in a separate question ‘How often do your available materials impact your ability to incorporate a laboratory-based activity?’ on a 1 (Never), 3 (Sometimes), 5 (Always) scale. The mean for this question was 2.64 which confirms the findings from the previous questions; there are times, more than rarely, when the materials’ availability is impacting their decisions, but it does not rise to the level of often.

As mentioned earlier and as part of the resources question from Table 6, the cost barrier might have been in terms of teachers' time to get materials, not a monetary expense. As seen above, time was an important factor identified by teachers as impacting their choice. In addition, since the teachers would have to obtain materials for their classroom using school funds, a few questions asked the teachers about the process or processes they had to go through to purchase materials. After asked to identify the process they use to purchase materials for their classrooms, 57.14% of the teachers answered no to the question ‘Does this process(es) ever hinder your ability to incorporate a laboratory-based activity when you want to do so?’ This suggests that the time for these processes is not high enough to impact the teachers' choices as the other time factors, class time and preparation time, identified earlier.

Overall, while the availability of materials impacts the teachers' decisions, the survey results indicate material availability is not a constant factor in the chemistry teachers' decision making process about their classroom practices.

LFLA teachers compared to HFLA teachers

Even though materials availability at their current levels did not significantly impact teachers' use of laboratory activities as a whole, certain teacher groups may be affected differently. Teachers not using labs at the recommended levels, or low frequency laboratory-based activity (LFLA) teachers, could have been facing greater or different barriers than the teachers using laboratory activities 3 or more times per month (HFLA group). Thus, a comparison of the two groups’ responses to the survey questions was conducted. Chi-square tests showed that teachers in the LFLA group only had different answers at a significance level less than 0.05 (p < 0.05) for eight questions on the survey, see Table 7 which also includes the one question with a significance level of 0.052.

Table 7 Survey questions which LFLA teachers answered differently than HFLA teachers

Question/Choice	LFLA N = 32	HFLA N = 106	F/χ^2	p
a Averages based on a scale of 1 (Never), 2 (Rarely), 3 (Sometimes), 4 (Often), 5 (Always). b Averages based on a scale of 1 (Does not impact my decision), 2 (Rarely impacts my decision), 3 (Often impacts my decision), 4 (Almost always impacts my decision).
If or when you are not able to use a laboratory-based activity, what do you do?
Skip laboratory-based activity completely	3.03	2.32	χ ^2 = 20.981	0.000
To what extent do you believe the following factors affect your choice to implement laboratory-based activities in your classroom?
Available materials that can be borrowed	1.97	1.75	χ ^2 = 9.671	0.022
Comfort in laboratory setting	2.19	1.66	χ ^2 = 10.211	0.017
Necessary preparation time	2.81	2.45	χ ^2 = 7.710	0.052
Reasons for implementing non-laboratory-based activities
I use them because I prefer them.	18.75%	2.83%	F = 10.218	0.001
I use them because they require fewer materials.	68.75%	38.68%	F = 8.958	0.003
I use them because they save money.	43.75%	25.47%	F = 3.932	0.047
How often do your available materials impact your ability to incorporate a laboratory-based activity?
1 (Never) to 5 (Always)^a	3.06	2.50	χ ^2 = 14.789	0.005
Does this process(es) ever hinder your ability to incorporate a laboratory-based activity when you want to do so?
Yes	62.50%	36.79%	F = 6.637	0.010

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Overall, the LFLA group were not blocked by the availability of materials or equipment more than the HFLA group or the funds available to them. The LFLA teachers might be more frugal than the HFLA teachers because on average they indicated they choose activities with fewer materials to save money more than the HFLA. However, in light of the other responses to the questions this frugality might be a personal choice rather than a necessity of their situation. The LFLA group had higher averages than the HFLA group in questions on ‘comfort in laboratory setting,’ ‘skipping’ activities when there is a barrier, and preferring non-laboratory activities. These answers could be viewed in terms of personal characteristics about teaching beliefs or self-efficacy in teaching. In addition, for the LFLA teachers the processes to purchase materials hindered them to a much higher degree than the HFLA teachers, despite the fact that the questions about the processes they go through had no difference in responses. The teachers who use laboratory-activities appear to be choosing to go through the process no matter what it is to get the materials, while those not using laboratory-based activities say the process gets in their way. Considering these responses, the fact that the LFLA teachers choose activities that require fewer materials more than the HFLA teachers could be due to the LFLA teachers not wanting or having the time to prepare activities with more materials rather than trying to reduce or save costs. Expense and availability of materials do not appear to be a barrier to the LFLA teachers, but rather some characteristic of the teachers which the survey did not measure. The interviews provide evidence to support this conclusion.

Teachers' comments from the interviews provide additional support that the difference in the LFLA group and HFLA group could relate to teachers' personal characteristics and choices rather than material funding and availability. When asked about a specific laboratory activity they chose not to do, a teacher from the LFLA group said

there was a few labs that I just kind of felt uncomfortable having you know my thirty students in my chemistry class go to the chem lab and do it without me having a really strong grasp of what was going on and you know… I guess another reason why I might not do a specific chemistry lab would be, they're just not structured in a way that my students would have to do the inquiry.

Materials were not the first thing mentioned by this teacher but rather his comfort in the lab or possibly the effort it would take to make the experiment into the right ‘structure.’ The other LFLA teacher interviewed said

‘I wouldn't see letting my kids loose with those in my classroom.’

In addition, when asked more generally about what ‘holds you back when there is a lab-based activity’ she said,

‘Graphing seems to be a big issue with them not understanding graphs, so I guess it's equipment and understanding is probably our biggest thing, so money and having to teach a lot of stuff, frontload a lot of, the ability to collect data and turn it into a lab.’

While she does mention equipment, ‘letting kids loose’ could be seen as her comfort in her classroom, and the second quote indicates that she would have to teach for them to do the laboratory activity. There was a personal focus in the two LFLA teachers interviewed.

The HFLA teachers on the other hand made the following comments to the same questions:

• ‘None that I couldn't do that I've chosen to do.’

• ‘No, not really. The only thing that constrains the labs that I would consider is time. You know, we have 50-minute class periods and so that constrains numerous types of labs that we can do.’

• I know one of the targets that I've always had for a lot of lab procedures is to kind of stay in that low cost category because I don't really have all that much of a science budget. After a while I think you become accustomed to operating just fine within that parameter.

The HFLA teachers differentiated laboratory activities in terms of the types of experiments, as the last comment suggests, doing experiments that work within their environment. As the second quote demonstrated, class time, not materials was the most commonly limiting factor mentioned by 7 of the 12 interviewed HFLA teachers. As another teacher said, what limits her is

‘the length of class time I have because our class periods are 42 minutes long and so I have to either make the lab fit within that class period or I have to be able to find a point to split the lab over two days.’

When materials were mentioned by the HFLA teachers as a limiting factor, it was in the context of long range planning as a barrier. As one teacher said,

‘You know once in a while I'm trying to think of something quick on my feet I'll be limited by the supplies.’

They also mentioned that they could not do specific activities because they were inappropriate for safety reasons:

‘there are some [experiments] that I haven't been able to do because they just, the chemicals aren't allowed in the high school chemistry room.’

These comments again represent a choice of specific activity, not activities in general, and they were not related to personal preferences as they were with the LFLA teachers. While only two of the interviewees happened to be in the LFLA category, they described more problems doing laboratory activities than all the HFLA teachers.

Limitations

There are two main limitations for this study. First, the study depended on self-reported data from the teachers about their practices. Secondly, the survey was only distributed to Iowa chemistry teachers, thus the results might not be generalizable to a larger audience. However, the sample size, range of participants teaching in different situations, and range of teaching experience provide findings which likely provide at least a piece of the picture for understanding secondary chemistry teachers. Finally, the study did not attempt to measure teachers' knowledge or beliefs about teaching and learning. While some of the prompts relate to non-monetary factors, we did not attempt to classify these or characterize this factors about the teachers. Rather, we simply grouped them as personal characteristics, which is a broad classification, and thus we cannot make any claims about the LFLA or the HFLA's teacher's beliefs or knowledge.

Discussion

Research question 1: the laboratory activities done in the chemistry classrooms

The majority of secondary school chemistry teachers in this study are doing laboratory experiments in their chemistry courses, which is similar to the rate reported by Smith (2013) who found 70% of secondary school chemistry teachers in the United States report using ‘hands-on/laboratory activities’ at least once per week. In addition, as Table 4 suggests, the chemistry teachers value these activities because when they are confronted with a barrier for a laboratory activity, a majority find an alternative laboratory activity or an alternative non-laboratory activity. They do not skip it or replace it with a less student-centered teaching method like lecture for example. This study cannot comment on the quality or effectiveness of the activities the teachers report using. Many may be traditional laboratory activities as suggested by the data from Table 3, and not reform-based as promoted by science teacher educators and NGSS, but the data from this study does not clearly address this. Continued research on the type and quality of the activities being used is needed to evaluate whether the laboratory activities align to current best practices for teaching chemistry. Given the importance of laboratory activities in the chemistry curriculum (Hofstein and Lunetta, 2003; ACS, 2012; NGSS Lead States, 2013), a higher usage rate of laboratory activities, especially those known to be aligned with best practices should continue to be encouraged and supported.

Research question 2: expense's impact on teachers' use of laboratory activities

Materials for laboratory activities, especially in chemistry, cost money and often require time and effort to purchase and prepare; they can be expensive. The results of this study indicate that at their current funding level materials do affect their choices at times, though not ‘often’ (Table 6). For the teachers doing the experiments, the interviews indicate materials might affect their choices of the laboratory activities, not their general use or rate of use. It is about what activities they do, not if they do them. The survey supports this conclusion as well because teachers tend to find alternative laboratory activities when they find they cannot do a laboratory activity they planned (Table 4), and they indicated alternatives to laboratory activities for pedagogical reasons in their classrooms not as substitutes for laboratory activities (Table 5).

In fact, the results of the study indicate that personal characteristics, possibly beliefs and knowledge, are more important than material funds or availability in determining teachers' classroom practice, supporting previous research (Roehrig et al., 2007; Cheung, 2011; Rushton et al., 2011; Van Driel et al., 2014) that identified these barriers as important. When teachers cite expense as a barrier to their teaching choices, it likely masks, possible unconsciously, the true barrier to their use of laboratory activities; for example, their self-efficacy, beliefs or knowledge for teaching chemistry. The LFLA teachers did not indicate cost of materials was a barrier on the survey at higher rate than the HFLA; yet the HFLA teachers engaged students in more laboratory activities than the LFLA teachers in similar funding and school environments. Comfort in the laboratory, personal choice of non-laboratory activities, going through the process of obtaining materials (which was the same processes for both groups) – these are descriptors which relate not to money but possibly beliefs, knowledge, or other personal characteristics. In most places, though not all, the current funding levels are sufficient for students to be regularly engage in laboratory activities. If students are not, and the funding levels are near the average for schools, something else is occurring.

Implications

While we did not evaluate the cost of more effective laboratory activities or the effectiveness of the activities the teachers reported using, the interviews especially indicated teachers were at times having to choose between activities because of funds. Thus, if the more appropriate and effective activity is more expensive they may be forced into less pedagogically sound choices due to expense. For curriculum developers and other reformers, this implies an importance that effective laboratory activities include materials ‘on hand’ for chemistry teachers or within cost reason of their budgets and their current spending level.

Funding is important as it did affect the teachers' choices at times, so changing the funding level would likely impact their choices to some degree, but it is likely not the solution for shifting teachers' practice to include more laboratory activities in chemistry. This study indicates that to improve their rate of laboratory usage, especially for those not currently using laboratory activities, increasing the funding for materials or the materials available for them to use will likely not impact their teaching practices. While reducing money for teachers will not solve the problem, funds which have been earmarked to buy teachers extra/more equipment might be more impactful on professional development to change beliefs or improve self-efficacy. This study did not collect enough data to discover what funding threshold might reduce a teachers' laboratory activity usage; more research is needed to understand it. But it is worth considering in a professional development program, for example, exactly how much money is needed for equipment for the teacher participants to carry out the program's goals in their classroom without over estimating, so that there is as much money as possible available to add another teacher to the program rather than fund excessive materials which will not significantly impact the teachers' practice.

Conflicts of interest

There are no conflicts to declare.

Appendix A

Survey questions

I am fully aware of the nature and extent of my participation in this project as stated above. By clicking on “Yes, I agree,” I hereby voluntarily agree to my participation in this project. I acknowledge that I have read this consent statement. I am 21 years of age or older.

○Yes, I agree.

○ No, I wish to exit the survey now.

Q2.1 What is your sex?

○ Female

○ Male

○ I prefer not to state.

Q2.2 What is the highest degree you have earned?

○ Bachelor of Arts

○ Bachelor of Science

○ Master's degree

○ Doctorate degree

○ Other ____________________

Q2.3 Are any of your degrees specifically designed to prepare educators? (i.e. Chemistry Teaching, Science Teaching, Mathematics Teaching)

○ Yes

○ No

Q2.4 What are your endorsement areas? Select all that apply.

□ Basic Science K-8

□ Basic Science 5-12

□ General Science 5-12

□ Physical Science 5-12

□ Biology 5-12

□ Chemistry 5-12

□ Earth Science 9-12

□ Physics 5-12

□ All Science 5-12

□ All Science 9-12

□ Mathematics K-8

□ Mathematics 5-12

□ Other ____________________

Q2.5 How many years have you been teaching? Please enter a whole number and include this year of teaching.

Q2.6 How many years have you been teaching chemistry? Please enter a whole number and include this year of teaching if you are or will be teaching a chemistry course at some time during the year.

Q2.7 Are the majority of classes you currently teach chemistry courses at any level?

○ Yes

○ No

Q2.8 Are you the only person teaching chemistry courses at any level at your school?

○ Yes

○ No

Q2.9 Are students at your current school required to take a chemistry course to graduate?

○ Yes

○ No

Q2.10 How many years have you been teaching at your current school? Please enter a whole number and include this year of teaching.

Q2.11 How would you classify your current school building? If you teach at more than one building, please select the most accurate response.

○ Rural

○ Suburban

○ Urban

Q2.12 What is the approximate size of your current school building? If you teach at more than one building, please select the most accurate response.

○ Fewer than 100 students

○ 100–200 students

○ 200–300 students

○ 300–500 students

○ 500–1000 students

○ 1000–1500 students

○ More than 1500 students

Q2.13 What category best describes the grade levels of your current school building? If you teach at more than one building, please select the most accurate response.

○ Middle school/Junior high

○ High school/Senior high

○ K-8

○ 6-12

○ K-12

Q2.14 How would you describe the financial situation of your current school building? If you teach at more than one building, please select the most accurate response for your district.

○ Low/Poor

○ Middle/Average

○ High/Wealthy

Q3.1 Please rate each statement to describe a typical laboratory-based activity in your classroom.

	Does not apply	Rarely applies	Sometimes applies	Often applies	Always applies
Students work with chemicals (e.g. NaOH, water)	1.	2.	3.	4.	5.
Students work with laboratory equipment (e.g. beakers, flasks, heating devices)	6.	7.	8.	9.	10.
Students are required to wear safety equipment (e.g. pants, closed-toed shoes, goggles)	11.	12.	13.	14.	15.
Students discuss findings as a class	16.	17.	18.	19.	20.
Students follow a given set of instructions	21.	22.	23.	24.	25.
Students make predictions	26.	27.	28.	29.	30.
Students take measurements	31.	32.	33.	34.	35.
Students make observations	36.	37.	38.	39.	40.
Students generate research questions	41.	42.	43.	44.	45.
Students create a procedure	46.	47.	48.	49.	50.
Students are provided with research questions	51.	52.	53.	54.	55.
Students are required to support conclusions with evidence	56.	57.	58.	59.	60.
Students answer post-lab questions	61.	62.	63.	64.	65.

Q4.1 For the purpose of this study, laboratory-based activities will be defined as “learning experiences in which students interact with materials and/or with models to observe and understand the natural world.” Therefore the following are NOT examples of laboratory-based activities: computer simulations, teacher demonstrations, filmed experiments, analysis of provided data, simulated lab experiments. Based on this definition, how often do your students do laboratory-based activities?

66. 0 times per month

67. 1–2 times per month

68. 3–5 times per month

69. More than 5 times per month

Q4.2 To what extent do you believe the following factors affect your choice to implement laboratory-based activities in your classroom?

	Does not impact my decision	Rarely impacts my decision	Often impacts my decision	Almost always impacts my decision
Safety equipment	70.	71.	72.	73.
Available chemicals or substances	74.	75.	76.	77.
Instrumental equipment (e.g. probes, spectrometers, analytic balances)	78.	79.	80.	81.
Laboratory space	82.	83.	84.	85.
Laboratory equipment (e.g. beakers, graduated cylinders)	86.	87.	88.	89.
Available procedural instructions	90.	91.	92.	93.
Necessary preparation time	94.	95.	96.	97.
Class time	98.	99.	100.	101.
Available safety warnings	102.	103.	104.	105.
Available materials that can be borrowed	106.	107.	108.	109.
Available waste removal instructions	110.	111.	112.	113.
Funds for waste removal	114.	115.	116.	117.
Technology (e.g. LoggerPro, Excel, computer applications)	118.	119.	120.	121.
Funds for materials	122.	123.	124.	125.
Comfort in laboratory setting	126.	127.	128.	129.
Other	130.	131.	132.	133.

Q4.3 If or when you are not able to use a laboratory-based activity, what do you do?

	Never	Rarely	Sometimes	Often	Always
Alternative laboratory-based activity	134.	135.	136.	137.	138.
Skip laboratory-based activity completely	139.	140.	141.	142.	143.
Alternative activity	144.	145.	146.	147.	148.
Delay laboratory-based activity until funds are available	149.	150.	151.	152.	153.
Lecture or discuss what would have gone on in the laboratory-based activity	154.	155.	156.	157.	158.

Q5.1 How often do your students do these non-laboratory-based activities?

	0 times per month	1–2 times per month	3–5 times per month	More than 5 times per month
Computer simulations (e.g. PhET simulations)	159.	160.	161.	162.
Filmed experiments	163.	164.	165.	166.
Analysis of provided data	167.	168.	169.	170.
Simulated laboratory experiment (e.g. web-based experiment)	171.	172.	173.	174.
Teacher demonstration	175.	176.	177.	178.
Other videos	179.	180.	181.	182.

Q5.2 For what reason(s) do you use the above activities (computer simulations, filmed experiments, analysis of provided data, simulated laboratory experiment, teacher demonstration, other videos)? Select all that apply.

1. I use them because they are equally or more valuable for student learning.

2. I use them because I prefer them.

3. I use them because they save time.

4. I use them because they require fewer materials.

5. I use them because they save money.

6. I use them because there are no safety restrictions.

7. I use them because it is easier to access necessary materials.

8. I use them because they are supplemental to my other classroom activities and lessons.

9. Other: ____________________

Q5.3 Have you used any of the following as alternatives in place of a laboratory-based activity? Select all that apply.

10. Computer simulation (e.g. PhET simulations)

11. Filmed experiments

12. Analysis of provided data

13. Simulated laboratory experiment (e.g. web-based experiment)

14. Teacher demonstration

15. Other videos

Q6.1 How often do your available materials impact your ability to incorporate a laboratory-based activity?

183. Never

184. Rarely

185. Sometimes

186. Often

187. Always

Q6.2 Please list some laboratory supplies or materials that you can regularly use for laboratory-based activities.

Q6.3 Please list some laboratory supplies or materials you wish you had access to.

Q6.4 How often does your department purchase the following with school funds for laboratory-based activities?

	Never	Yearly	Every few years	When funds are available
Disposable items or substances that must be purchased from a chemical supply company	188.	189.	190.	191.
Disposable items that may be purchased at local stores	192.	193.	194.	195.
Measuring equipment	196.	197.	198.	199.
Glassware or plasticware	200.	201.	202.	203.
Safety equipment	204.	205.	206.	207.
Technology hardware (e.g. probes, spectrometers, analytic balances)	208.	209.	210.	211.
Technology software (e.g. LoggerPro, Excel, computer applications)	212.	213.	214.	215.
Textbooks, laboratory manuals	216.	217.	218.	219.
Curriculum materials	220.	221.	222.	223.

Q7.1 What process(es) must you go through in order to use funds from your department or school to purchase materials for laboratory-based activities? Select all that apply.

16. My department receives funds which are split evenly between teachers.

17. My department receives funds, and decisions for spending are made collaboratively.

18. I am given a set amount of funds yearly that I can use as I wish.

19. I play no role in the purchasing of supplies.

20. I or my department needs verbal approval

21. I or my department needs written approval with an application

22. My department needs no other approval when spending allotted funds.

23. Other ____________________

Q7.2 Does this process(es) ever hinder your ability to incorporate a laboratory-based activity when you want to do so?

224. Yes. Please briefly explain: ____________________

225. No. Please briefly explain: ____________________

Q8.1 Have you spent personal funds on laboratory materials or supplies in the last three years?

226. Yes

227. No

Q8.2 Approximately how much money, on average, have you spent with personal funds on laboratory materials each of the last three academic years?

228. $0

229. $1–100

230. $101–200

231. $201–300

232. $301–400

233. $401–500

234. $501–1000

235. More than $1000

Q8.3 What items do you purchase when spending personal funds on laboratory materials or supplies? Select all that apply.

24. Disposable items that must be purchased from a chemical supply company

25. Disposable items that may be purchased at local stores

26. Measuring equipment

27. Glassware or plasticware

28. Safety equipment

29. Technology hardware (e.g. probes, spectrometers, analytic balances)

30. Technology software (e.g. computers, LoggerPro, Excel)

31. Textbooks, laboratory manuals

32. Curriculum materials

Q9.1 Whether you indicated that you have spent personal funds or you have not spent personal funds on laboratory materials or supplies, why did you choose to do or not to do this?

Q10.1 Is there anything else you would like to share about your experiences incorporating laboratory-based activities in your classroom?

Appendix B

Interview protocol

Consent for voluntary teacher interview

Prior to beginning any interview question during the phone interview, the following will be asked:

Hello. I am calling you today about your laboratory teaching practices. You have previously been sent an interview consent form. I will be recording our phone interview today. The purpose of the audio recording is for more accurate data analysis in case anything is missed by me. If you are willing to continue with the interview and are ok with the audio recording, please say so.

If you have any questions during the interview, please let me know. With your consent, we will continue with the interview questions.

Interview questions

I will be asking you about the laboratories you use in your classroom, the reasons for using them, the alternatives to labs that you may use, and how different aspects of cost may impact your use of labs. You may recognize some of the background questions from the survey as well.

1. How long have you been teaching chemistry?

2. How long have you been teaching at your current school?

3. How would you describe the financial situation of your school? Why?

4. What is the size of your school?

5. Can you tell me about one of your favorite laboratory-based activities?

6. Can you think of another one of your favorite ones?

7. What are your reasons for using laboratory-based activities in your classroom?

8. Has there ever been a laboratory-based activity that you couldn’t do? Why couldn’t you do it?

9. Can you think of another laboratory-based activity that you haven’t been able to do?

10. What seems to hold you back or keep you from doing the laboratory-based activities that you want to do?

11. What do you when you can’t do a laboratory-based activity you want to do?

12. How do you feel about the use of computer simulations, online laboratories, filmed experiments, teacher demonstrations, or other alternatives in place of student laboratory-based activities?

13. Do you ever use these types of alternatives in place of a laboratory-based activity?

14. Have you ever spent your own money on laboratory-related supplies? Why or why not?

15. What kinds of items do you purchase with your own money? Why?

16. Did you expect to spend your own out-of-pocket money when you first began teaching? Why or why not?

17. Is there anything else you would like to share about your experiences incorporating laboratory-based activities in your classroom?

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