Improving Students' Practical Laboratory Techniques through Focused

Chapter 8

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Improving Students’ Practical Laboratory Techniques through Focused Instruction and Assessment John P. Canal,*,1 Jimmy Lowe,*,2 and Rosamaria Fong2 1Department

of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada V5A 1S6 2Department of Chemistry, British Columbia Institute of Technology, 3700 Willingdon Avenue, Burnaby, BC, Canada V5G 3H2 *E-mails: [email protected] (J.P.C.); [email protected] (J.L.)

Undergraduate chemistry laboratory courses are delivered through hands-on exploration of the lecture material, however, students face challenges in performing the physical actions of the experiments and these are dependent on the method the instructions are delivered. A student who knows and understands proper laboratory techniques will have an easier time with the experiment, be less stressed, work more safely, obtain results that match expectations and re-enforce the lessons learned in lecture. Recently, we have re-evaluated and modified the way the laboratory technique instruction is delivered to students in our laboratory courses. In order to focus the attention of students on the proper way to use the glassware and common apparatus used in most undergraduate laboratories, a Laboratory Techniques experiment was developed as well as laboratory technique centered exercises. We will present our efforts to improve student learning, instructor observations, data and graphing skills to support the effectiveness of these initiatives.

© 2016 American Chemical Society Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Introduction The role of the undergraduate chemistry laboratory is to provide students with an opportunity to explore theory through physical manipulations, while developing proper laboratory technique skills. To maximize learning, students need to develop proper laboratory techniques, as poor techniques will result in poor data, which will cause confusion when students try to link theory to practice. One of the first major works that highlighted the pedagogical importance of learning proper laboratory techniques was Michael Faraday’s Chemical Manipulation, written in 1827 (1). In this work Faraday wrote that “The importance of instruction in manipulations has long been felt by the author and the deficiency existing in the means of teaching it (1).” The result of Faraday’s work was an acceptance of laboratory technique instruction as an important component of the laboratory experience (2, 3). The methods employed by instructors to impart to students laboratory skills have varied greatly since the initial works by Faraday and are the subject of numerous publications (2–7). One of the more common methods employed is the “elbow instruction” or more commonly known as “feedback”, where an instructor observes a student performing a task in the laboratory and provides instructions on how to improve his/her technique (2). Our study is based on the work undertaken at the Department of Chemistry at Simon Fraser University (SFU) and the British Columbia Institute of Technology (BCIT). The entire BCIT Chemical and Environmental Technology diploma program was recently revised. This was an opportunity to change how first year laboratories could be taught more effectively to students. The updated BCIT CHEM 2204 laboratory course lead to a collaboration with SFU who were carrying out a course review of how laboratory techniques were taught in CHEM 126. Both courses are the second laboratory course in the students’ programs. In our attempt to improve our students’ learning experience in the laboratory we expanded our laboratory technique instructions based on the “feedback” method. Through students’ improved results, we will provide evidence of the effectiveness of our approach. The emphasis on the practical and transferable skills aids the students to prepare for future coursework and employment. We discuss some of the differences at both institutes in dealing with class size, resources and the use of teaching assistants. For example, the longer second-term at BCIT, provides an opportunity to evaluate students using Microsoft Excel for data manipulation and graphing.

Approaches to Laboratory Techniques Development Simon Fraser University (SFU) The first year chemistry laboratory courses at SFU follow the standard expository (also termed traditional, verification or cookbook) style employed at many post-secondary institutions (4, 6, 8). Each laboratory period is four hours long, where students are given enough time to complete the experiment and submit laboratory report sheets before the end of the session. At the start of each laboratory period, a pre-lab lecture is given either by the instructor to the 138 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


entire class (~80 students) or by the Teaching Assistants (TA) to smaller groups of generally less than 20 students. The pre-lab lectures highlight many of the important aspects of the experiment, such as reminders of safety considerations, explanation of experimental steps, information about the report sheets, and laboratory technique instructions/demonstrations among others. A drawback of the general pre-lab lecture is that students do not know which components of the lecture are the most important. If an instructor wants to highlight the importance of laboratory technique instructions, the pre-lab lecture is a poor way to stress this as students tend to assume that all material in the pre-lab lecture is of equal importance (9). There is also no mechanism to discern if students have received the message given in the pre-lab lecture. In regards to laboratory techniques development, there is no time to practice the skills highlighted in the pre-lab lecture (4). Also, the pre-lab lecture assumes that students are paying attention, and that they have come to the laboratory prepared to do the experiment (10). In our laboratory course, laboratory technique instructions were taught as part of the greater context of the course material. In order to stress to students the importance of learning proper laboratory techniques we introduced a Laboratory Techniques experiment into our curriculum (CHEM 126: General Chemistry Laboratory II). The introduction of the Laboratory Techniques experiment into the General Chemistry Laboratory II and not the General Chemistry Laboratory I (CHEM 121) was by design. As our students have diverse educational backgrounds, their laboratory experience varies with different skill sets learned and instructions given. By the end of CHEM 121, all students would have been exposed to the same level of instruction and skill development. As CHEM 121 is a pre-requisite of CHEM 126, we were able to use their CHEM 121 experience as a baseline in the development of the Laboratory Techniques experiment. With the new Laboratory Techniques experiment, students are presented with common laboratory techniques in one experiment at the beginning of the semester. Students are exposed to the same information previously taught in CHEM 126, but the method used to deliver the information has changed. As the new experiment is solely dedicated to proper laboratory technique skills development, students understand the importance of learning how to use the glassware and instrumentation correctly. This message is reinforced during the semester through spot-checks of their skills during the experiment, as well as the introduction of a practical exam, where their laboratory skills are tested (5). The effectiveness of new methods on student learning in laboratory courses is most commonly investigated through the use of student surveys (8, 10–14). Students are also examined through practical tests, written exams and through the development of student-generated videos where they explain and perform a specific skill (8, 11, 12). Although aspects of our assessment included a practical exam and qualitative observations, the overall effectiveness of our approach was determined by a direct analysis of the students’ laboratory skills and not their understanding of the theory or opinion on its effectiveness. We analyzed the experimental data to determine if there was an improvement in the precision of the data, which would occur if students understood and performed the laboratory techniques correctly. 139 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

Laboratory Techniques Experiment: Plan 1 The initial version of the Laboratory Techniques experiment was broken into two parts. Part 1 consisted of instruction and practice time on six selected laboratory skills, while Part 2 required a review of the Laboratory Techniques manual and completion of a laboratory report sheet. Plan 1: Part 1


Laboratory techniques commonly employed in our first year experiments, as well as two theory based lessons comprised the topics of the Laboratory Techniques experiment. The topics were grouped as follows: • • • • • •

Pipettes Burette setup Titration Balances Volumetric glassware (Graduated cylinder and Volumetric flasks) PowerPoint presentations on: Lesson on Writing Skills (Purpose and Conclusion) and Calibration and Spectroscopy

The laboratory space consisted of 3x3 rows of benches with six students per bench (three per side). The room could be conveniently split into six stations with nine students assigned per station (54 students in total), hence the reason for the six topics. At each station students watched a demonstration given by the Teaching Assistant (TA) or instructor on the proper use of the glassware/instrument. Students were given the opportunity to practice the laboratory skills while the TA/instructor provided feedback. Students had to show the TA/instructor that they had mastered the skill by correctly performing to the TA/Instructor tasks such as “correctly filling the volumetric flask to the mark” or “dispensing 4.25 mL from the burette”. Incorrect steps were corrected and the student allowed to repeat the task. After 15 minutes, which was the time given for students to learn and practice the skills, they would rotate to the next station. The cycle was repeated until all students had gone through each station. At this point, students who had mastered all skills would proceed to Part 2 of the experiment, while those that did not were required to practice further until he/she could perform the technique correctly. Rarely did students require the extra help. Plan 1: Part 2 After the physical manipulation of the glassware/instrumentation in Part 1, students were asked to read a nine page Laboratory Techniques manual, which is a modified version of a Laboratory Techniques manual developed at BCIT. The manual covered all the topics of Part 1, except for the materials on the PowerPoint slides. A sample from the manual is provided in Figure 1 below. In addition to the Laboratory Techniques manual, a laboratory report sheet was provided to the students. The report sheet was due at the end of the laboratory 140 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

period. It was marked and returned in the following laboratory session. The laboratory report sheet consisted of 15 questions. The answers were either given in the demonstration at the technique stations or could be found in the Laboratory Techniques manual. Sample questions include: Why do you need to rinse (acclimatise) the pipette? Is it OK to pipette the liquid into the pipette bulb? Explain. Which finger do you use to control the liquid level in the volumetric pipette?


1. 2. 3.

Figure 1. A section of the Laboratory Techniques manual used in Part 2. Courtesy of Mrs. Rosamaria Fong, unpublished work.

141 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

Reinforcement of the Message


The Laboratory Techniques experiment was performed in the second week of the semester. This allows students enough time to practice and apply their skill set when performing other experiments. The importance of using correct laboratory skills was reinforced throughout the semester. Students were reminded to use correct laboratory techniques in the pre-lab lectures. During the semester, TA spot-checks were done to assess students’ laboratory skills, and feedback was provided to them. A practical exam was also introduced into the course in which students’ laboratory skills were tested. Laboratory Technique Experiment: Plan 2 Although the students successfully developed correct laboratory technique skills through the method presented in Plan 1, the logistics of running Plan 1 presented limitations. Plan 1 was hindered in its ability to be applied to other situations. Our laboratory space conveniently allowed for six stations. With a maximum enrollment of 54, each group had a maximum size of nine students. With a different room size/configuration or increased enrollment capacity, the experiment would not work. Also with 54 students, 3 TAs were assigned to this course. For a laboratory section with a smaller enrollment there could be only 2 TAs. Plan 1 required a total of 5 TAs/instructor no matter the enrollment size, which meant volunteers had to be found to run the experiment. Running this experiment for students who were absent was also problematic as each station had to be set up individually. Due to the renovation of our building, we moved into a new space, which accommodated 80 students and 4 TAs in two rooms. Plan 1 would not work in this setup, therefore, it was modified and we developed Plan 2. Plan 2 removed the space and enrollment capacity limitations and allowed the experiment to be more adaptable to different situations. TA’s/Instructor demonstrations were replaced with PowerPoint presentations and an exercise sheet was added. Plan 2: Part 1 The laboratory techniques demonstration stations of Plan 1 were replaced with PowerPoint presentations, with the exception of the Manual Titration demonstration. This demonstration was shown to groups of 15-20 students. A test run of Plan 2: Part 1 was done with all demonstrations removed. It was found that both the Manual Titration demonstration and the PowerPoint presentation were required for the students to accurately learn the skill of a manual titration. Our students’ success rate in mastering the other skills did not diminish with the removal of the demonstrations and adoption of the PowerPoint presentations. All PowerPoint presentations were available to students on the laboratory computers (One computer per pair of students in the laboratory room), and they described the correct techniques to use/operate the glassware/instrument. The PowerPoint slides were accessible online after the laboratory session. A sample slide describing a Manual Titration is given in Figure 2. 142 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Figure 2. Sample slide from the Manual Titration PowerPoint presentation.

Accompanying the PowerPoint presentations was the exercise sheet, which served two functions. Firstly, the exercise sheet was used to ensure that students read the PowerPoint presentation. Students had to answer on the exercise sheet questions that were embedded in the PowerPoint slides. Secondly, the exercise sheet was also used as a way to check whether students had mastered the laboratory techniques. Each exercise sheet included at least one task related to each technique, which students needed to perform for their TA. Each TA supervised a maximum of 20 students. If the students were successful in completing the task, the TA would sign the exercise sheet and award the student one point. In order to complete this portion of the experiment, students were required to obtain the TA’s signature for all laboratory techniques in order to prove that they had mastered all the laboratory skills. Students were given enough time to practice the technique until he/she mastered the skill, thus all students eventually receive full marks. A sample set of questions/tasks from the exercise sheet related to Burette and Manual Titration is shown in Figure 3 below.

Plan 2: Part 2 Once the students were able to perform all the techniques correctly they were given the same report sheet employed in Plan 1: Part 2. The same level of reinforcement was used throughout the semester. Students were reminded to use the correct laboratory techniques during their laboratory sessions. TA spot-checks were done to evaluate students’ laboratory skills, and provide feedback to the students. A practical exam was also given to test students’ laboratory skills. 143 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Figure 3. Sample exercise sheet.

Plan 1 versus Plan 2 From a pedagogical point of view, both plans were found to be effective tools in teaching laboratory technique skills (this will be discussed further in the Results and Discussion section below). From the logistical point of view Plan 2 was superior over Plan 1. Plan 2 could easily adapt to new situations. The benefits of Plan 2 include the following: • • •

• •

•

The Laboratory Techniques experiment is no longer constricted by the laboratory space. More topics can be added to the Laboratory Techniques experiment. The Laboratory Techniques experiment is no longer restricted by the total number of students or the total number of TAs. There is no need to find volunteers to help with the experiment. As there is only one demonstration, “make-up” experiments are not difficult to set up. Each student receives the same information about the techniques. This was not guaranteed in Plan 1 with different TAs giving the same presentation in different laboratory sections (9). When reviewing the laboratory techniques, students have two resources to access: the PowerPoint presentations and the Laboratory Techniques manual.


Two years after implementing Plan 2, we moved to our final laboratory space. Even with a very different layout of the laboratory space, we were able to continue to run the experiment successfully without modification to Plan 2.


Results and Discussion (SFU) The effectiveness of this experiment was initially examined through qualitative observations. We found that students were more comfortable with the equipment, there were fewer problems with student data, and we were no longer asked by students “Why is my experimental data wrong when I did everything correctly?” We also performed a quantitative study of the effectiveness of this experiment. We theorized that since each student performs the same experiment, once students were taught correct laboratory techniques, the average values across all the laboratory sections should be very similar, and we should see an improvement in the precision of the student data when we compare student data prior to the implementation of the Laboratory Techniques experiment. (Table 1) Care was taken to minimize the external factors that could alter students’ results in this study. We chose to examine students’ results from Experiment 5, “Determination of an Equilibrium Constant” and Experiment 6, “The Solubility Product of Potassium Hydrogen Tartrate” from the CHEM 126 course laboratory manual. These experiments were chosen since both experiments did not undergo any revisions during the period of the study. The two experiments were also chosen as they made extensive use of the volumetric glassware such as burettes, volumetric flasks and pipettes, which requires proper laboratory techniques in order to achieve accurate measurements. For consistency, during the length of the study the same instructor also ran the experiments. We were able to collect students’ experimental results before and after the implementation of the Laboratory Techniques experiment, which allowed us to compare, quantitatively, the effect of the Laboratory Techniques experiment. Our students had a known laboratory technique skill set before completing this experiment, as almost all students would have taken the prerequisite laboratory course (CHEM 121) at SFU. The laboratory technique skill set developed in CHEM 121 did not change during the course of this study, therefore we are able to compare the different approaches of Plan 1 and 2, with the previous method used in CHEM 126 and make meaningful conclusions. Within each semester, the laboratory was run numerous times on different days, which we refer to as “lab sections”. For both experiments, students entered their results online in addition to their report sheet. This provided us with an electronic copy of the student values, which were used in our study. The value on the report sheet was used to ensure that the electronic data was entered correctly. For each lab section, we analyzed the student results to calculate an average value. We excluded all outliers that differed from the average value by more than three times the standard deviation. For semester 1 there were 4 outliers in the Experiment 5 data with 11 outliers for Experiment 6. For semesters 2-7 on average there was less than 1 outlier per semester for Experiment 5 and 4 outliers 145 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


per semeter for the Experiment 6. As shown in Table 1, for each semester we compared the standard deviation of the average value from each lab section. We limited the analysis of the student data to seven semesters as we did not have any data before semester 1. After semester 7 we made revisions to both experiments, which would have introduced too many variables into our study. From the data shown in Table 1, it is evident that Plan 1 and Plan 2 versions of the Laboratory Techniques experiment were successful in improving students’ laboratory skills through improved precision of the data. For Experiment 5, in all of the semesters after semester 1, we saw an increase in the precision of the student values as evident by the decrease in the standard deviation of the student results. The same trend is seen in Experiment 6, with the exception of semester 4. Although the standard deviation is still lower than that of semester 1, it is much higher than the rest of the values. During this semester we noticed that within the lab sections the student results would vary by more than 100%, but there was high precision within groups of students in the lab section. We suspected an issue with one or more sets of stock solution bottles. Although the erroneous results were reproducible, we were not able to definitively determine the cause. The information that can taken from the semester 4, Experiment 6 data, is that even with an additional source of error the precision of the data was still better than for Semester 1. This illustrates the effectiveness of the Laboratory Techniques experiment.

Table 1. Summary of student results from CHEM 126 (SFU) Experiment 5

Experiment 6

Method used

Semester

Number of Students

S.D.a

S.D. (x10-4)

“Old” way

1

262

0.142

1.91

Plan 1

2

96

0.061

0.22

3

157

0.035

0.61

4

296

0.050

--b

5

118

0.047

0.81

6

142

0.034

0.03

7

273

0.049

0.12

Plan 2

a

Standard deviations of the average values from each laboratory section within a semester. b This semester, experiment 6 had an unexplained source of error resulting in groups of students with results that were more than double of that of the other students in the same laboratory section. We suspect that there was an issue with one or more of the stock solutions bottles. The standard deviation of the data with the anomalies removed was 1.28x10-4, while for the whole data set it was 1.69x10-4.



After semester 7, instructional videos were introduced in these experiments. Videos on the techniques studied became available for students to view before their laboratory session. The effect of the videos on the precision of the students’ results has been difficult to assess since the experiments had undergone revisions, but a survey of the students found that they felt that the videos were an effective learning tool and their use should be expanded. The use of instructional videos as a teaching tool has been found to be an effective method to teach laboratory techniques through numerous studies (10, 12, 13, 15). The similar results of Plan 1 and 2 (Table 1) illustrated that the same message presented in two different methods can be used to impart laboratory technique skills to the student. The material presented in the Laboratory Techniques experiment was always part of the course. Previously, specific components of laboratory techniques were presented as part of the laboratory lecture for a particular experiment. A reason for the success of the Plan 1 and 2 versions of the Laboratory Techniques experiment was in grouping all the material into one dedicated experiment, laboratory skills became an important aspect of the course and students gave it greater attention.

British Columbia Institute of Technology (BCIT) BCIT is a polytechnic institute that offers a variety of programs where students are placed in “sets” (cohorts averaging 20 in size) to complete their studies together. The Chemical and Environmental Technology (CENV) program is a two year program (35 weeks per academic year) with two cohorts starting annually. Courses are taken over four consecutive school terms and students graduate with a diploma. Careers achieved by CENV graduates include analysts and research technologists in chemical laboratories. In order to prepare students, we focused on the following: • • •

Enhance students’ awareness and knowledge of chemical laboratory techniques required for employability. Provide greater opportunities for mastery of chemical laboratory techniques by practice and continuous feedback. Ensure that our evaluative component of chemical laboratory techniques is standardized, unbiased, and that the scoring methodology provides useful feedback to students for improvement.

The aim of the program is to teach practical laboratory skills in a cooperative learning environment. Our teaching methodology is designed to enhance learning through performance assessment and continual feedback (2). Here we describe the teaching methods used in the two first year chemistry courses in the CENV program, CHEM 1121 and CHEM 2204.



CHEM 1121 and CHEM 2204 Students entering the CENV program have varying chemistry backgrounds, ranging from students with university training to students with the minimum chemistry prerequisite of grade 12 high school chemistry. The students’ skills in a chemistry laboratory vary tremendously from year to year. As a result, CHEM 1121, a traditional chemistry course, is taken in the first term of the CENV program to provide students the necessary chemistry background (4, 6, 8). The course consists of 3 hours of lecture and a 3 hour laboratory period per week. During the laboratory periods, students are exposed to a wide variety of practical laboratory techniques as well this course serves as a foundation for career preparation. In the laboratory portion of CHEM 1121, students are introduced to basic volumetric glassware and weighing techniques. This included the correct use of volumetric flasks, pipettes, burettes, and different methods of weighing. Students were taught how to apply these techniques to perform manual titrations, gravimetric analysis, chromatography, and volumetric analysis. Since for many students this was the first formal introduction to chemical laboratory techniques, students were not graded on their laboratory techniques. However, to encourage students to achieve accurate results, they were graded on their analyses. The acceptable accuracy range of their results was less stringent than more advanced courses, such as CHEM 2204. A demonstration of the relevant techniques was given at the start of each laboratory period. Over the course of the term, students were given many opportunities to practice these laboratory techniques such that they become accustomed with the flow of the steps involved. Once students reached a comfortable level, a one-on-one peer review exercise was introduced where students performed laboratory techniques to a peer (16). The purpose of this exercise was to prepare students for a job interview, where one could be asked to demonstrate a laboratory technique to a certain level of competency. In order to quantify the level of competency and standardize an unbiased evaluative component, we introduced laboratory technique assessment scoring rubrics for each laboratory technique. For example, Figure 4 shows a sample of the laboratory technique rubric used to measure the competency of using a burette during a manual titration. Scoring rubrics helped students determine specifically what was required of them and these tools also help new instructors provide consistent demonstrations across multiple course sections (17). The peer review exercise allowed students to learn and evaluate chemical laboratory techniques. Students, as reviewers, gained experience in assessing the laboratory techniques demonstrated by their peers. Using the laboratory technique rubric, students evaluated each other and practiced providing verbal constructive feedback. For the student being reviewed, they gained experience in maintaining their composure while demonstrating their skills. This exercise helped prepare students for the next chemistry course, CHEM 2204, where they were evaluated via formal laboratory technique assessments by an instructor who used the same laboratory technique rubric. 148 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Figure 4. Laboratory Assessment Rubric for Technique 1 – Use of Burette CHEM 2204 is the second term course in the CENV program. It is a 20-week course for 3 hours per week with the following laboratory components: • • • • •

Techniques and Practice (T&P) Traditional chemistry laboratories Data manipulation and Graphing Practical assessments (PA) Final laboratory exams

An open course website was set up for students to access course information (18). The reference text for this course is the “Chemical Technicians Ready Reference Handbook” (19). Techniques and Practice (T&P) We introduced a set of T&P laboratories, where students were given additional opportunities to practice laboratory techniques. These T&P laboratories alternated with traditional chemistry laboratories (see below), where the experiments are chosen with procedures relying largely on using skills learned. During the T&P laboratories, students were expected to continue peer reviewing each other using the technique rubric given. No mark was awarded for this component of the course. 149 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

Traditional Chemistry Laboratories


There were five traditional chemistry laboratories where students carried out laboratory analyses, perform calculations, and reported the results of their analyses. These laboratories were based on titration methods, gravimetric analysis, weighing, colorimetric analysis and extraction. The reported results were graded out of a score of ten. Depending on the laboratory, a maximum of six marks were awarded for accuracy and precision, and the other marks were distributed for correct calculations and observing significant figure rules in their calculations and results. Data Manipulation and Graphing Another employable skill to emphasize for students is data manipulation of experimental results (20, 21). There were five graphs in this component of the course. Demonstrations were given in class on the use of Microsoft Excel to manipulate data on a spreadsheet, analyze and report statistical errors, and produce graphs with proper labelling. To expand on the benefit of cooperative learning, 20% of the graphing mark was awarded for the ability of students to review another student’s graph (22). Students printed a copy of their graph and exchanged graphs with another student for peer review. Using the peer reviewer’s feedback, students made changes to their original graph and compiled a set of the following three graphs to the instructor: • • •

Graph 1 is Student A’s original graph. Graph 2 is Student A’s graph that was reviewed by Student B. Student B’s comments were annotated on this graph. Graph 3 is Student A’s final corrected graph.

The instructor marked Graph 2 and Graph 3 for a total score of 10 using the following guideline: • •

Student A is graded on his/her ability to peer review Student B’s graph. Student A’s comment will appear on Student B’s Graph 2. (2 marks) Student A’s Graph 3 is graded on the completeness of the graph. (8 marks)

A sample submission of the graphs from Student A is provided in the Results and Discussion section below (Figure 5). Practical Assessments (PA) There were two 15-minute one-on-one Practical Assessments (PA) in the course: PA 1 in Week 8 and PA 2 in Week 15. Table 2 summarizes the laboratory techniques that students were responsible to learn to demonstrate their knowledge. Because of the 15-minute time constraint, students could only be effectively assessed on two techniques. On the day of the assessment, students were randomly assigned two techniques. During their assessment, the instructor asked students to 150 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

explain keywords specific to the technique that was being assessed. Students were expected to communicate calmly and articulate scientifically sound responses. In the time given, students were required to complete a minimum number of steps for each technique. The instructor observed the student and graded the student with the same laboratory technique rubric that they have used in their peer review exercise.

Table 2. Summary of the techniques assessed in week 8 and week 15


Practical Assessments – Techniques assessed Week 8

Use of a Pipette, Weighing, Use of a Bottle-Top Dispenser, Gravity Filtration, Rotary Evaporator

Week 15

Use of a Burette, Use of a Volumetric Flask, Preparation of Standard Solution, Titration

The following week, the instructor conducted a one-on-one formal discussion about each student’s proficiency in carrying out the techniques assessed. This usually required between 3 to 5 minutes, where the instructor gave constructive feedback to communicate the following: • • •

What the student has mastered, and the extent of that mastery on the two techniques that were assessed. What the student needs to improve on to perfect the techniques. What the student needs to improve on in terms of their communication skills.

Final Laboratory Exams The goal of the final laboratory exam was to help students prepare for their future career by providing situations for authentic learning (23). In the final two weeks of the course, students carried out two laboratory exams. Table 3 summarizes the grading scheme of the laboratory exams. These exams were completed individually, with the entire class carrying out the laboratory exam at the same time. This is a more realistic situation found in a workplace, where the attention is not usually focused one-on-one. The instructor played the role of a laboratory supervisor who monitors a group of laboratory analysts as they carry out an analysis at their own bench space. Rules were set for the usage of the equipment. For example, since there was a limited number of analytical balance, students were restricted to weighing one sample at a time. The instructor noted when students use incorrect techniques. Each incorrect technique was a demerit of 0.5 marks, up to 7 marks. 151 Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Table 3. Laboratory exam grading scheme Laboratory Techniques

7 marks

Accuracy of Results

6 marks

Calculations

4 marks

Organization and the ability to follow a procedure

3 marks

Total

20 marks

CHEM 2204 was designed to help the student focus on the finer details of the laboratory techniques that may be missed while observing a laboratory demonstration. In addition to the techniques previously discussed by SFU, the full version of the BCIT Laboratory Techniques manual included the following procedures: gravity filtration, use of the rotary evaporator, calibration and use of the bottle-top dispenser.

Results and Discussion (BCIT) Overall, students who conscientiously practiced their laboratory techniques while being reviewed by a classmate using the scoring rubrics decreased their anxiety of making mistakes. Similar to SFU, students demonstrated more motor proficiency than the first set of attempts with the techniques and confidence when carrying out the laboratory techniques. We have not carried out a detailed numerical analysis of student performances because the students’ backgrounds vary significantly from year to year (i.e. we do not have a controlled set of students with the same chemistry background). Due to time limits of the one-on-one practical assessment, each student also cannot be assessed on all the techniques practiced in the T&P weeks. We remind students during the term that all laboratory techniques will be assessed in the final laboratory exams. Table 4 shows the typical results for a recent group of students for the Practical Assessments (PA) and final laboratory exams. The scoring rubric from the PA was reviewed with each student in a one-on-one discussion. Students have used the analogy of “the road test for a driver’s license” when they carried out the practical assessments. There are always two to three students who score below 50% on the first practical assessment due to anxiety. We advise those students to modify their preparation specific to their performance and incorporate study skills, group work or student services that reduce anxiety. Graduated CENV students commented that the practical assessments helped them prepare for their second year industry practicum and job interviews which required a demonstration of a laboratory technique (e.g. laboratory technician).


Table 4. Results for Practical Assessments and Final Laboratory Exams Average % a

Standard Deviation

Range of Marks

74

3

22-97%

76

3

50-95%

Final Laboratory Exam I

73

3

51-90%

Final Laboratory Exam II

71

2

56-90%

Evaluative Component Practical Assessment Week 8 b Practical Assessment Week 15

c


a

Results from 32 students. PDF files of all the scoring rubrics can be found on the course website (18). b Two of the following techniques assessed: use of a pipette, weighing, use of a bottle-top dispenser, gravity filtration, and rotary evaporator c Two of the following techniques assessed: use of a burette, use of a volumetric flask, preparation of a standard solution and titration

In the past 6 years that the CENV program has been offered, our feedback indicates that students are more aware of the following expectations: • • • •

Competency in the laboratory techniques students need to master at the end of the first year of the CENV program. Competency in preparing graphs to display a data set. Competency to communicate cohesively and logically using appropriate chemically correct keywords. Competency to work collaboratively and provide constructive criticism.

Our training better prepares students for the second year of their program as well as employability after graduation. For the collaborative learning environment featured in the courses, students see the advantages of receiving immediate feedback and working collegially with their instructor and peers to improve their own learning (22). Students view the grading system to be fair because they get a second chance to check for improvement. The peer review of graphing assignments promoted a cooperative learning environment, team work, and communication among students. Figure 5 is a typical set of graphs that students submitted for grading. Without the peer review process, Student A would have submitted Graph 1 for grading, possibly missing many important aspects of the graph. However, Graph 1 was peer reviewed by Student B, who clearly marked up the incorrect points in Graph 2. Student A was, therefore, able to correct his/her mistakes and submit Graph 3 for grading. This was a discipline-based process which allowed students to experience the benefit of working collaboratively. It also provided students with the opportunity to implement corrections and submit their best work.



Figure 5. Graphing and Peer Review submission.



Conclusion In order to effectively teach students proper laboratory technique effort must be made to make the subject important. This can be accomplished in the form of a dedicated Laboratory Techniques experiment or through the use of technique specific assessment rubrics that carry over numerous courses with different levels of evaluators (i.e. their peers and instructor). The goal of developing sound laboratory technique and transferable skills in our students was modified to meet the objectives of the programs at SFU and BCIT. At SFU, both iterations of the Laboratory Techniques experiment improved the laboratory technique skills of the students, as evaluated through qualitative observations and the quantitative results shown in Table 1. Through improved laboratory skills, students were better prepared to perform experiments, obtain results that match theoretical predications and become more comfortable in the laboratory setting. At BCIT, the “learn, practice, do, review” cycle built into the first year chemistry courses has shown to instill confidence and skills in the students in the CENV program. Although students enter the program with varying skill levels, the first year chemistry courses help to set a baseline of laboratory skills expectations, develop and refine students’ laboratory techniques. The courses are developed to give the students transferable job skills. Based on the BCIT Student Outcomes Reports for Certificate and Diploma Graduates, 79% of the graduates reported the program as useful in helping them find employment (24).

Acknowledgments The laboratory technique videos were supported by a Teaching and Learning Development Grants from the Institute for the Study of Teaching and Learning in the Disciplines (ISTLD) and the Teaching and Learning Centre (TLC) at Simon Fraser University (25). Debbie Owen (SFU) is acknowledged for her assistance in the development of the Laboratory Techniques experiment. We also would like to thank all students who “tested” our ideas in the development of these learning tools. We are grateful to SFU and BCIT for their support and funding.

References 1. 2. 3.

4. 5.

Faraday, M. Chemical Manipulations; Wiley: New York, 1827. DeMeo, S. Teaching chemical technique: A review of the literature. J. Chem. Educ. 2001, 78, 373–379, DOI: 10.102/ed078p373. Burgard, D. A. An introduction to the general chemistry laboratory that makes a lasting impression concerning laboratory safety. Chem. Educator. 2005, 10, 427–429, DOI: 10.1333/s00897050966a. Domin, D. S. A review of laboratory instruction styles. J. Chem. Educ. 1999, 76, 543–547, DOI: 10.1021/ed076p543. Hofstein, A. The laboratory in chemistry education: Thirty years of experience with developments, implementation and research. Chem. Educ. Res. Pact. 2004, 5, 247–264, DOI: 10.1039/b4rp90027h. 155

Schultz et al.; Technology and Assessment Strategies for Improving Student Learning in Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

6.

7.

8.


9.

10.

11.

12.

13.

14.

15.

16.

17.

Cacciatore, K. L.; Sevian, H. Incrementally approaching an inquiry lab curriculum: Can changing a single laboratory experiment improve student performance in general chemistry? J. Chem. Educ. 2009, 86, 498–505, DOI: 10.1021/ed086p498. Galloway, K. R.; Brats, S. L. Measuring meaningful learning in the undergraduate chemistry laboratory: A national, cross-sectional study. J. Chem. Educ. 2015, 92, 2006–2018, DOI: 10.1021/acs.jchemed.5b00538. Dunlap, N.; Martin, L. J. In Advances in Teaching Organic Chemistry; Duffy-Matzner, J. L., Pacheco, K. A. O., Eds.; ACS Symposium Series 1108; American Chemical Society: Washington, DC, 2012, pp 1−11, DOI: 10.1021/bk-2012-1108.ch001. Majerle, R. S.; Utecht, R. E.; Guetzloff, C. J. A different approach to the traditional chemistry lab experience. J. Chem. Educ. 1995, 72, 718–719, DOI: 10.1021/ed072p718. Key, J.; Paskevicius, M. Investigation of video tutorial effectiveness and student use for general chemistry laboratories. J. App. Learn. Technol. 2016, 5, 14–21. Towns, M.; Harwood, C. J.; Robertshaw, M. B.; Fish, J.; O’Shea, K. The digital pipetting badge: A method to improve student hands-on laboratory skills. J. Chem. Educ. 2015, 92, 2038–2044, DOI: 10.1021/acs.jchemed.5b00464. Jordan, J. T.; Box, M. C.; Eguren, K. E.; Parker, T. A.; Saraldi-Gallardo, V. M.; Wolfe, M. I.; Gallardo-Williams, M. T. Effectiveness of studentgenerated video as a teaching tool for an instrumental technique in the organic chemistry laboratory. J. Chem. Educ. 2016, 96, 141–145, DOI: 10.1021/ acs.jchemed.5b00354. Popova, M.; Bretz, S. L.; Hartley, C. S. Visualizing molecular chirality in the organic chemistry laboratory using cholesteric liquid crystals. J. Chem. Educ. 2016, 93, 1096–1099, DOI: 10.1021/acs.jchemed.5b00704. Mathew, J. M.; Grove, N.; Bretz, S. L. Online data collection and database development for survey research in chemistry education. Chem. Educ. 2008, 13, 190–194, DOI: 10.1333/s00897982133a. Canal, J. P; Hanlan, L.; Key, J.; Laveiri, S.; Paskevicius, M.; Sharma, D. Chemistry Laboratory Videos: Perspectives on Design, Production, and Student Usage. In Technology and Assessment Strategies for Improving Student Learning in Chemistry; Schultz, M., Schmid, S., Holme, T.; , Eds.; ACS Symposium Series 1235; American Chemical Society: Washington, DC, 2016; Chapter 9. Ponrello, J. K. Enhancing the skill-building phase of introductory organic chemistry lab through a reflective peer review structure. J. Chem. Educ. 2016, 93, 262–269, DOI: 10.1021/acs.jchemed.5b00655. Chen, H.; She, J.; Chou, C.; Tsai, Y.; Chiu, M. Development and application of a scoring rubric for evaluating students’ experimental skills in organic chemistry: An instructional guide for teaching assistants. J. Chem. Educ. 2013, 90, 1296–1302, DOI: 10.1021/ed101111g.



18. Fong, R. BCIT CHEM 2204. nobel.scas.bcit.ca/courses/wpmu/chem2204/ laboratory-2/ (accessed July 20, 2016). Note: Scoring rubric PDFs are linked in the Practical Assessment Section. 19. Shugar, G. J., Ballinger, J. T. Chemical Technicians’ Ready Reference Handbook, 4th ed.; McGraw-Hill: New York, 1996. 20. Rubin, S. J.; Abrams, B. Teaching fundamental skills in Microsoft Excel to first year students in quantitative analysis. J. Chem. Educ. 2015, 92, 1840–1845, DOI: 10.1021/acs.jchemed.5b00122. 21. Ashraf, S. S; Marzouk, S. A. M.; Shehadi, I. A.; Murphy, B. M. An integrated professional and transferable skills course for undergraduate chemistry students. J. Chem. Educ. 2011, 88, 44–48, DOI: 10.1021/ed100275y. 22. Berry, D. B; Fawkes, K. L. Constructing the components of a lab report using peer review. J. Chem. Educ. 2010, 87, 57–61, DOI: 10.1021/ed8000107. 23. Lombardi, M. M. Authentic learning for the 21st century: An Overview. Educause Learning Imitative Website. https://net.educause.edu/ir/ library/ pdf/eli3009.pdf (accessed March 1, 2016) 24. BCIT Student Outcomes Reports for Certificate and Diploma Graduates 2012 Edition website. http://www.bcit.ca/files/ir/ pdf/gradoutcomes_ dacso _2 page_2012.pdf (accessed March 22, 2016); pp 288−289. Note: The Chemical Sciences Program was renamed the Chemical and Environmental Technology Program after a curriculum change in 2010. 25. SFU Teaching and Learning Development Grant Home page. http:// www.sfu.ca/tlgrants.html (accessed March 25, 2016).


Improving Students' Practical Laboratory Techniques through Focused

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