The Chemical Educator, Vol. 11, No. 3, Published on Web 04/06/2006, 10.1333/s00897061018a, © 2006 The Chemical Educator
A Possible Format for a Noncookbook, but Noninquiry-Style, Laboratory Manual
Roberto Ma. S. Gregorius
Department of Chemistry, University of Texas–Pan American, Edinburg, TX 78539, firstname.lastname@example.org
Received August 30, 2005. Accepted December 5, 2005.
Abstract: A general chemistry laboratory manual was developed with the objective of providing a system from which students could not approach the use of the manual as though it were a cookbook. All the experiments incorporated in the manual were of the verification type and were typical of experiments conducted in such fashion. The manual system was composed of (a) a printed manual, (b) a compact disc of supporting material (CD), and (c) a laboratory report notebook. For each experiment, the printed manual contained a background explanation of the experiment, a derivation of any mathematical formulas to be used in the experimental design, a terse description of the procedures for each experiment, and a postlaboratory set of questions. The CD contained concept and report-writing tutorials; a virtual laboratory for some experiments, prepared using Macromedia’s Flash authoring tool; and short video clips of actual techniques. All of this was accessible from a PDF version of the printed manual found on the CD. The terse nature of the procedure descriptions forced the students to prepare for each experiment ahead of time using the contents of the CD. A preliminary report of student performance is reported and referenced to the typical performance of students in the traditional, verification-type laboratory courses.
Student performance and attitudes in the general chemistry laboratory have been an ongoing concern at the author’s institution. One of the key issues considered was the tendency of students to enter into the laboratory experience without having adequately prepared for it. It was noted that students habitually followed the described procedural steps without showing any evidence of having read the steps beforehand or having any clear understanding of the reasoning behind each step. Attempts at inducing students to prepare ahead of time for each experiment have involved prelaboratory quizzes (fall 1998), prelaboratory reports (fall 1999), and random verbal quizzing during the experiment period (fall 2002). These efforts had no discernable effect on the overall performance of the students (see Figure 1).
Although, several research efforts have shown that an inquiry-based laboratory experience may improve student understanding [1–6], the consensus of the faculty teaching in the general chemistry program at the author’s institution is that, with the background of our students, it would not be appropriate to use an inquiry format for our laboratory courses at this time. The arguments put forth by those who oppose the development of an inquiry–based general chemistry laboratory experience revolve around the poor training of incoming college students. The American College Testing (ACT) scores for the state of Texas are lower than the national average and those of the students from Region I (the region where most of our students come from) are even lower than that of the state’s average (for example, the mean national science reasoning ACT for 2001 is 21.0, that for Texas is 20.3, and that for Region I is 18.4). This is corroborated by the mean SAT scores of incoming college students (national: 1021, Texas: 990, Region I: 915). This is compounded by the perception that incoming students have had very little or a poor laboratory experience in chemistry. Despite this determination, however, there still remained a need to ensure that students would be induced to go through the process of preparing for each laboratory experiment so that they could properly benefit from the experience. An accommodation was needed so that the prelaboratory preparations that are inherent in inquiry-based laboratory experiences would be incorporated into a verification-type experiment design.
The laboratory manual described here is the result of the author’s effort to redesign the laboratory manual system while still using the current laboratory experiments in order to avoid potential logistics issues. We wanted to try to force the students to prepare ahead of time, avoid students’ treatment of the laboratory manual as a cookbook, but also to keep the experience as safe as possible and within the perceived skill level of our students. A laboratory manual system comprising a printed laboratory manual, a compact disc (CD) of supporting information presented in an engaging manner, and a laboratory report notebook was developed with the express objective of forcing the students to recognize the need of preparing ahead of the laboratory period and to do so for each experiment.
Laboratory Manual System Content and Format
Printed Laboratory Manual. The printed laboratory manual we designed had several important features not normally found in the typical verification-type laboratory manuals. Figure 2 is an excerpt from the experiment (with markers inserted for addressing) wherein students were required to prepare and standardize a 0.2 M NaOH working solution from a 6 M NaOH stock solution and standardize this against potassium hydrogen phthalate (KHP). This solution is used for the following experiment involving the analysis of antacid tablets. Figure 2a shows the main procedural step, which is terse by design. In this experiment, the student is only
told to prepare a 0.2 M working solution from a (6 M) stock solution. In the next step (Figure 2b), again the student is simply told to prepare a buret for use in this experiment. Thus, the procedural steps were designed simply to guide the students as to the appropriate steps in the flow of the experiment, but the details of how the particular step should be accomplished was not described.
Each procedural step statement is immediately followed by a “things to think about” subsection (Figure 2c and 2d). This section was added to guide the students as to how they might consider doing each procedural step. Thus, in step 1 of the procedure, the student is reminded of the dilution equation (M1V1 = M2V2), and in step 2 of the procedure, the student is asked several questions that, when considered, should indicate to the student the purpose of cleaning the buret and the appropriate steps to clean a buret. Each of the “things to think about” is followed by white space (Figure 2e, not shown here for space reasons), in which the students were expected to write their answers to the guide questions.
The objective of such a design is to prevent students from coming into the laboratory without having read through the experiment and with the expectation that they could do the experiment by simply following, line-by-line, the steps described in a typical “cookbook-style” laboratory manual. The expectation was that students would, prior to coming to the laboratory, look through the procedural steps, consider the guide questions, go through the support material provided in the accompanying CD, formulate a protocol for that particular procedural step, and write that protocol in the space provided.
A background information section, similar to what can be found in typical verification-type laboratory manuals, was included. More importantly, whenever applicable, the experiment was grounded in a single mathematical equation. This was meant to give the student an overall basis for understanding the experimental design. For instance, in the experiment discussed previously, the following equation is derived in the background section:
where MNaOH, the molarity of the prepared sodium hydroxide working solution, is the objective of the experiment. This value can be obtained by finding the mass of KHP used (gKHP), the volume of sodium hydroxide used in the titration (LNaOH), and using the molar mass of KHP (MMKHP). The experimental design is then discussed as a process in which the variables in the equation are precisely obtained. Thus, it was hoped that by developing the experimental design around a mathematical equation, the student would see why particular steps had to be taken. In this case, the student was expected to see that the experiment was designed to give them the values for gKHP, MMKHP, and LNaOH.
CD of Supporting Materials. With this new format, however, there was a danger that students would simply not be able to perform the experiment, would not have the initiative or capacity to do the research to flesh out each procedural step, or would not be able to design appropriate procedural steps based on their own research. An even greater danger was that the procedures would be interpreted in such a way that placed the student physically at risk. With this in mind, a CD was produced and delivered along with the printed laboratory manual. The CD contained everything that was deemed necessary in order to completely fill in or flesh out the terse procedural statements and to help students find answers to the questions posed in the “Things to think about” section. In effect, the CD not only became the one-stop research resource for students, but it also provided a controlled flow of information such that, with a little effort from the students, the correct or applicable information could be obtained.
The CD contained a portable document format (PDF) version of the printed laboratory manual produced using Adobe Acrobat, a series of video clips of laboratory techniques and safety instructions, concept tutorials, a virtual laboratory bench, and report tutorials. The PDF file was the main window for accessing all other supporting material. The printed laboratory manual inset boxes (Figure 2f) indicate the availability of support files. In the PDF version of the printed manual, this box is an active link to the particular file described. Thus, the expectation was that the student would open the PDF file in the CD, link to the support material at each juncture, and, from an understanding of the ideas presented in the support material, fill in or flesh out their printed laboratory manual. The printed laboratory manual becomes their main resource within the actual laboratory, but
the CD is the main resource for fleshing out the printed manual.
Videos of Laboratory Techniques. To ensure the safety of the students and the application of appropriate techniques, we included over two hours worth of video clips on laboratory techniques and safety. These videos were created in-house with the aid of our publisher and featured our own students doing particular laboratory techniques and discussing safety issues. We made sure that no particular video clip was more than five minutes long and that each only spoke to one particular topic. These video clips are similar in style to the Journal of Chemical Education “Chemistry Comes Alive!” software series . Videos such as these have been shown to have a positive effect on the student’s ability to conduct the experiment .
Concept Tutorials. To further ensure that students understood the principles or theories involved in each experiment, concept tutorials were developed using the Macromedia Flash  authoring tool. As much as possible, the focus of the concept tutorials were kept within the framework of what Johnstone  calls the macroscopic (experience), (symbolic) representation, and submicroscopic (particulate conception). Thus, each concept tutorial focused on what the student might see in the laboratory, how the student might visualize and conceptualize what is observed, and how this might be expressed in symbolic terms. Greenbowe and Sanger [11–17] have shown that animations have a positive effect on student learning. Thus, Flash was used to prepare these tutorials with the hope that the animation and interactivity afforded by this authoring tool would successfully engage the students and provide them with the opportunity to develop their own interpretation of the concepts focused on in each experiment.
Figure 3 shows some screen shots of a concept tutorial that supports an experiment concerning the gravimetric analysis of the hydrate to anhydrate transformation. Figure 3a shows the introduction of a generalized symbolic representation of the chemical equation, Figure 3b shows the inclusion of an animated presentation of the macroscopic experience, and Figure 3c shows the particulate conceptualization of the symbolic statement and macroscopic experience. The magnifying glass shown in Figure 3c first hovers over the macroscopic representation of the crucible; the crucible is magnified and a cut-away shows the hydrate inside the crucible. The magnifying glass then moves over the hydrate sample, and the molecular representation of the hydrate is shown. Finally, all three representations are shown side-by-side to illustrate the connection of the three ways of viewing the experience (Figure 3d)—the crucible is heated and the hydrate sample slowly changes to anhydrate as the attached molecules of water leave the starting molecule. Similarly, in the concept tutorial, which concerns the gas-law equations (Figure 4), the student is given the opportunity to explore gas-law relationships pertaining to the experiment. In Figure 4a, the student is introduced to the simulation conventions. The student may drag the mouse pointer over the items on the screen and an explanation is provided for that particular component. The student is then allowed to manipulate the elements of the simulation (in this case, cooling the apparatus, Figure 4b). The macroscopic experience is then either referred or connected to an animated representation of the effects of heating and cooling on the trapped gas particles (Figures 4c and 4d).
Virtual Laboratory. For experiments that the author thought might benefit from a student attempting the experiment in a simulation, a virtual laboratory bench (complete with an apparatus that is handled similarly to the way they would be in the laboratory and representing only items found in our laboratories) containing specific experiments was prepared and included in the CD. Studies have shown that providing a a virtual laboratory experience has benefits for student learning [8, 18]. The intent was to allow the students the opportunity to try the more intricate experiments and gain some confidence in their ability to do the actual experiment in the laboratory. Figure 5 shows a series of screen shots of the virtual environment supplied in the CD. Figure 5a shows the opening screen, Figure 5b shows an experiment chosen (gravimetric analysis of a hydrate) and the chemical cabinet open, Figure 5c shows the progress of the experiment in which glassware and equipment have been taken out of their respective compartments, and Figure 5d shows a sample being heated to constant weight. A virtual laboratory setting was made for four out of the ten experiments incorporated in the General Chemistry I laboratory manual. The other experiments for which a virtual laboratory was not included were either observational in nature (introduction to chemical reactions, observing the line spectrum emissions of different gases, etc.) or were better served with videos (Charles’s Law) or separate simulations available in the concept tutorial (calorimetry). A similar determination was made for the experiments in the General Chemistry II laboratory manual.
Report Tutorial. The author is not aware of any studies showing that postlaboratory report tutorials have any effect on the overall performance of students; however, the author felt that it was necessary to incorporate such tutorials in order to allow the students to focus on preparing for the experiment instead of thinking of what was needed in order to write a report. A report tutor, which walks the student through an actual write up and discusses the significance of each entry in the report, was prepared using Macromedia’s Flash authoring tool. Whenever possible, sample data would be shown and the student would be asked to calculate results based on the data. If the student realized that s/he was not capable of doing the calculations or if the student made an error in the calculations as determined by a comparison of the student’s answer versus those expected from the data provided, the report tutor supplied step-by-step reasoning based on the mathematical formula previously discussed. Again, Flash was used to prepare this material in the hope that the animation and interactivity would engage the student. Figure 6 shows a series of screen shots of the report tutor for the NaOH standardization experiment. Figure 6a shows how the main report sheet from the laboratory manual is replicated in the tutorial. Figure 6b shows the report sheet with representative data, with the student being asked to calculate the expected result from the given data. Should students get a different answer than the one provided, they are walked through the calculation based on the mathematical expression first described in the printed manual’s background information (Figures 6c and d).
Report Notebook. A report notebook was included in the package; however this notebook did not contain anything that might be considered innovative. The notebook contained carbonless copy paper (original) that was handed to the
instructors for grading, while the copy remained bound to the notebook allowing for students’ review. The laboratory report contained defined spaces for logging data (see Figure 6a for an electronic simulation of this space), observations, discussions of results, and answers to postlaboratory questions.
Similar to the traditional “cookbook” system previously employed in the author’s institution, the technology-infused system provided ten experiments over ten weeks for both the first-semester (lab 1) and second-semester (lab 2) general chemistry laboratory course. Midterm and final examinations were given and these constituted 50% of the student’s final grade. The remaining 50% came from the laboratory reports. There were twenty-two students per section; the instructor of record handled two to three concurrent sections, with one senior student teaching assistant per section. Students worked in pairs or in small groups. Group work was used for logistic purposes as opposed to educational purposes.
In the traditional setting, approximately thirty minutes of a two-and-a-half-hour period is spent for discussion of the experiment to be done as well as quizzes or report collection, with the remainder of the time being spent on actual laboratory work. Students worked in pairs or in small groups (maximum of 5 students per group) depending on the experiment. The author, as well as senior student teaching assistants, would then circulate through the laboratory floor to offer assistance, test student knowledge, and make sure that experiments were done under safe conditions.
Unlike in the traditional system implementation, no further inducements to prepare for the laboratory work was made in the technology-infused system. No prelaboratory reports were required, nor were prelaboratory quizzes provided. More importantly, no prelaboratory lectures or instructions were given. The students were expected to begin working as soon as the period began. At the very beginning of the semester, a one-and-a-half-hour period was spent introducing the new laboratory manual system in which the students were instructed on the optimum use of the laboratory manual. It was emphasized in strong terms that students were expected to go through the support material provided in the CD in order to flesh out the procedural steps. Students were repeatedly told that no help would be given to students who came to the laboratory unprepared as evidenced by coming to the laboratory with printed manuals that had improperly or insufficiently filled “Things to think about” sections.
In the technology-infused system, the author and teaching assistants’ duties became more of a policing of the students. They would circulate through the laboratory floor to check on whether students wrote meaningful statements in their laboratory manual’s “Things to think about” section. The student’s effort to flesh out the printed laboratory manual instructions was taken as evidence that the student had made an effort to prepare for the day’s experiment. Assistance in the experiment was only provided if the author or his teaching assistants were satisfied that the student made a good effort in preparing for the current experiment. Moreover, students who habitually came into the laboratory unprepared were paired or grouped together with similarly unprepared students. This policy may appear harsh and potentially unsafe, but it was deemed necessary to send the message that improper prelaboratory preparation would not be tolerated. It is the experience of the author, as well as other’s in the author’s department that this kind of penalty is sometimes necessary at the beginning of the course in order to instill on the students that the instructors have every intention of adhering to certain protocols or structures. The necessity of such penalties (for some of the author’s students) serve to reinforce the belief that it is not so much that the students do not have the capacity to prepare for the laboratory experience, but that the students simply choose not to prepare if there are no immediate and effective repercussions.
Observations and Discussion
After each laboratory period, two students (out of a possible twenty-two from each section) were requested to remain for interviews. These interviews were open-ended and designed to gain maximum feedback on the students’ perception of the program and how the student felt the program might be improved. As such, while the interview would begin with asking the students how they felt about the supporting materials, the interview was allowed to progress in whatever direction the student felt was most important. It was felt that such a system of interviews would provide greater feedback then a more structured survey. The interviews indicated that students ranked the videos of laboratory techniques as the most useful for understanding and conducting each experiment. The concept tutorials were most often reviewed and fully studied prior to the midterm and final exams. Report tutorials were used mostly to make the students feel secure that their understanding of calculation protocols were correct, and the virtual lab was often found too cumbersome to use, took too much time for the students, and was not as engaging as initially expected. The interviews conducted suggested that, with the exception of the virtual laboratory, each of the other components provided students with something of value at different points of the whole laboratory course. Students particularly liked the interactivity afforded by the concept and report tutorials and the directness of the videos and tutors.
The first two to three weeks were very difficult for the instructors, especially for those teaching lab 2 in the fall semester (the first time this system was applied). The department had to face many complaints from students who thought that the laboratory manual was made unnecessarily difficult. Complaints came especially from students who were in lab 2 and who had experienced lab 1 in the traditional system of using a cookbook-style laboratory manual. Complaints also came from students who were repeating the lab 1 course and had already experienced lab1 in the traditional format. Moreover, instructors who did not properly introduce the intricacies of the laboratory manual system (who neglected to provide the 1.5-h introductory lecture concerning the details, support files, and proper use of the laboratory manual system) were faced with many complaints from students who were simply and utterly lost. There were also some complaints that the laboratory course was being made unnecessarily difficult for a one-credit course (the laboratory courses in the author’s institution have separate catalog numbers and are treated as an independent course); however, after about the third week, students showed signs of understanding how the laboratory manual actually supplied them with all the information they needed. Many students actually apologized for their earlier complaints, and, after the midterm examinations, most of the
students reported having a preference for this system over the traditional cookbook-style system.
Interviews with student teaching assistants who had prior experience with the traditional lab manuals and were currently using the new laboratory manual system showed an overwhelming preference for this new laboratory system. The most common comment was that they were relieved from the extra work of instructing the students minute-by-minute on how to safely and properly conduct each procedure. There was consternation for some assistants however in finding that, especially in the early part of the semester, students were not able to find the pertinent material for the experiment. Further investigation showed that these incidents often happened in sections where the instructor neglected to give a proper introduction of the most efficient use of the new laboratory manual system.
In order to have some indication of the efficacy of this new technology-infused laboratory system, a comparison was made with the preceding year’s student performance. It was not necessary to compare performances to other years (beyond those of the preceding year) as there was virtually no difference in student performance from year to year prior to this new system (see Figure 1). Laboratory reports were graded by the teaching assistants using notes that were prepared by the author. Midterm and final examinations were given and this comprised 50% of the student’s overall grade. Examination questions were similar as those given in the traditional setting and broken down into four categories: (a) theory, questions regarding the background concept of each experiment; (b) procedure, questions designed to probe whether the student understands the reason for each procedural step; (c) data manipulation , testing whether the student can calculate results based on similar data gathered from actual experiments; and (d) data analysis, testing whether the student understands the effect of errors and bad procedures or techniques on the experiments’ results. The overall grades are curved, but the data shown here are grades before any curve has been applied.
While the technology-infused laboratory manual was used by all lab 1 and lab 2 instructors in the author’s department in the 2003–04 school year, the author’s own laboratory course load consisted of three sections of lab 1 in the fall semester and two sections of lab 2 in the spring semester.
Figure 1 indicates that various attempts at getting the students to prepare for each experiment [prelaboratory quizzes (fall 1998), prelaboratory reports (fall 1999), and random verbal quizzing (fall 2002)] had no significant effect on the performance of students. A marked improvement in the performance of students taking lab 1 was observed when the technology-infused laboratory manual system was applied (Figure 7); however, it is not within the scope of this study to pinpoint exactly what part of the laboratory manual system is the main reason, if in fact there is one single reason, for the marked improvement observed for students taking lab 1. Furthermore, the grades presented here are only those from the author. Grades from other instructors cannot be made available. Moreover, no such improvement could be said for students taking lab 2 in the spring (Figure 8). While it could be argued that students in lab 2 (in either traditional or technology-infused systems) have already had the prior training of lab 1 and the department has already corrected some of the flaws inherited from their poor or nonexistent high school training or perhaps that the difference in student demographics and maturity for lab 2 may have had some effect on this result, it is again difficult to pinpoint why no difference could be observed (except for the changes in the percentage of students getting F and D) in spring lab 2. A more statistical analysis was considered inappropriate as the results provided here are only those for one semester each of lab 1 and lab 2. Moreover, for reasons other than student learning outcomes, the author’s department has chosen not to continue using this system and have reverted to the more traditional cook-book style of laboratory manual. It is meaningful to consider, however, that, even if no significant difference could be observed in student performance between those in the traditional system and the technology-infused system, the performance of those students in the technology-infused system was obtained without further instructions from teaching assistants or the author. Some value is imbedded in allowing the students to research the necessary information. It is hoped that others might try and investigate this approach further .
References and Notes
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19. For those seeking copies of the laboratory manual and support materials, the laboratory manual is no longer in print because it was used solely by the author’s department; however, review copies are available from the publisher: Outernet Publishing, Inc. http://outernetpublishing.com/ (accessed Mar 2006).