Article Cite This: J. Chem. Educ. XXXX, XXX, XXX−XXX
pubs.acs.org/jchemeduc
Problem-Based Approach to Teaching Advanced Chemistry Laboratories and Developing Students’ Critical Thinking Skills Joseph G. Quattrucci* Worcester State University, 486 Chandler Street, Worcester, Massachusetts 01602, United States S Supporting Information *
ABSTRACT: A new method for teaching advanced laboratories at the undergraduate level is presented. The intent of this approach is to get students more engaged in the lab experience and apply critical thinking skills to solve problems. The structure of the lab is problembased and provides students with a research-like experience. Students read the current literature, develop new experiments for the curriculum, and then present the work in both oral and poster format. From the instructor’s observations, it was found that students take ownership of their experiments and typically apply themselves more than in a traditional lab setting. Student feedback about this approach has been overwhelmingly positive. KEYWORDS: Upper-Division Undergraduate, Laboratory Instruction, Physical Chemistry, Interdisciplinary/Multidisciplinary, Problem Solving/Decision Making
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BACKGROUND Worcester State University is a small public liberal arts school with a student population of approximately 6500 undergraduate and graduate students. The student body is diverse and composed primarily of full-time students. The chemistry department offers a bachelors degree in science and has a typical curriculum. Several years ago we sought to provide the chemistry majors with a more nontraditional lab experience. While research opportunities with the 10 faculty members of the department exist for the students, these projects are faculty driven and may not always be of interest to some students. There are several approaches to teaching lab as discussed by Domin1 and Johnstone and Al-Shuaili.2 These include expository, inquiry, discovery, and problem-based learning. Expository (traditional) is the most widely used approach to teaching lab. These are recipe style protocols where students simply follow a predetermined procedure and instructions for data analysis. They are teacher-centered leaving very little problem solving for the student. Students simply go through the motions without much thought or reflection about the concepts covered in the lab. They do, however, provide the learner with the opportunity to develop practical skills such as using glassware, mixing solutions, and making observations, to name a few. Lagowski states that this style of laboratory is merely an “exercise designed to consume minimal resources whether these be time, space, equipment, or personnel”.3 While there are good reasons to take such an approach in certain circumstances, the effectiveness of this style of lab has been called into question.2,4,5 Domin5 suggested that traditional laboratories (expository) do not facilitate higher-order © XXXX American Chemical Society and Division of Chemical Education, Inc.
cognitive skills. The development of problem-solving skills and critical evaluation of the results are lacking. In an analysis of 10 general chemistry manuals, Domin found that the majority of these manuals had students operating in the lower-order cognitive skill set of Bloom’s6 taxonomy. While learning does occur in traditional laboratories, inquiry (or open inquiry), discovery (or guided inquiry), and problem-based teaching styles can help students develop higher-order cognitive skills and keep the learner intellectually engaged. While there are differences between inquiry, discovery, and problem-based laboratories, as described in the literature,1,2 these styles move toward being more student-centered, rather than teacher-centered. Students take responsibility for their learning, and the instructor serves as a guide. While these approaches are more intellectually active compared to the more passive approach of expository laboratories, they too have been criticized, primarily for being time-consuming. Additionally, the inquiry approaches, open and guided, have been further criticized for their inductive approach to learning.2,3 The criticism appears to focus on student preparedness. Namely, the student will have difficulty discovering a concept without a foundation of knowledge. Discovery-based learning has received positive feedback from students in the lecture setting, however. Works by Farrell et al.7 and Hinde and Kovac8 are a couple of examples of discovery-based learning that have received positive outcomes. Therefore, the method in which Received: July 24, 2017 Revised: December 11, 2017
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DOI: 10.1021/acs.jchemed.7b00558 J. Chem. Educ. XXXX, XXX, XXX−XXX
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future endeavors. Additionally, we want the students to improve their ability to read and critically evaluate the scientific literature, to be more intellectually engaged in activities that require a higher-order thinking skill, like problem solving, to work more independently from instructor oversight, to practice delivering scientific presentation, and to provide them with an opportunity to work on topics that interest them. These are in alignment with some of the university and department learning outcomes. In this course, there are no predetermined scientific concepts or experimental techniques that are being taught to the student. Each group of students determines what they want to learn and to what extent. It is expected that each student, despite their preparedness, expands on their current knowledge. This is ensured by assessment throughout the semester which includes a weekly write-up of what they have read and learned. They are individually questioned on the material periodically. If their responses reflect a lack of understanding, they are asked to revisit the material to get clarification and report back to the instructor. The groups are tasked with developing two new experiments that can be incorporated into the required Physical Chemistry Lab I course. The experiments should be interdisciplinary, e.g., biophysical chemistry, or physical organic chemistry, but can be strictly physical chemistry. This criterion is to hopefully demonstrate the relevance of physical chemistry with the other disciplines, something lost on a lot of students. They are asked to make use of the available instrumentation which includes IR, fluorimeter, GC−MS, and NMR, as well as other commonly found instruments in an undergraduate program. A copy of the syllabus is supplied in the Supporting Information. Although we have applied this approach to a physical chemistry lab, it can be used in any advanced lab.
these approaches are implemented must be considered. In recent years, more instructors have been embracing these models, in particular, problem-based learning. Approaches using this model have been proposed at all levels of the curriculum from first9−12 and second year13−15 to more advanced lectures and laboratories including, analytical/ environmental chemistry,16−21 biochemistry,22,23 and physical chemistry.24 Problem-based learning has been used in medical education since the 1960s. While there is some debate over the effectiveness of this style of learning in medical education25−27 and a call for more concrete educational research28,29 on the topic, there appears to be consensus that students are more engaged and find the approach more rewarding. Furthermore, recent studies in the chemistry literature suggest that putting students in a setting of cooperative problem-based learning does improve their problem-solving skills.30,31 With this in mind, we sought to make changes to one of our upper-level laboratories. Although it is obvious from the literature that the approach can be executed in an introductory course, we felt it would be more beneficial to the student at the advanced level. By this point, students should have developed the necessary laboratory skills that are emphasized in traditional laboratories at the lower level. Furthermore, they should possess the requisite knowledge on which to build. Within this course, they can focus on developing further their existing knowledge, learning new content, and developing problemsolving skills and critical thinking, the higher-order cognitive activities desired. In a typical problem-based lab or activity, a problem statement is given to the students. In some cases, the problem statement is based on real world topics to which the students can make a connection. This is done in order to get the student engaged and motivated. For example, Hicks and Bevsek created a series of problem-based modules in which students learn quantitative analysis through the pretense of cleaning up a contaminated water source.11 Students in a problem-based setting devise their own (usually within a group) procedure for an experiment that attempts to answer the problem. They are responsible for collecting and analyzing the data and formulating a conclusion. The instructor serves as a guide during this process. The structure of our Physical Chemistry Lab II course was modified to be a problem-based learning environment to provide the students with a research-like/real-world-like experience. The class is a two credit hour course that meets once a week for 4 h. It is an upper-level elective lab course that is offered every two years in the spring semester. Students enrolling in the course must have completed Physical Chemistry Lab I and are usually at the end of completing their degree. Prior to the course being offered, students are given an overview of what the course entails and what is expected of them. This ensures that the students registering for the course understand its format and the role of the instructor. The students that have taken the course range in preparedness, but are mostly the academically stronger students, with GPAs of 3.0 or higher. Students form their own groups of two or three based on interest. For example, students that are concerned with environmental issues may form a group with the intent of creating a lab that includes environmental chemistry. Groups of four have been tried but led to one or two of the members contributing less than the others. As stated above, the goals of the course are to provide the students with a “research” experience and help better prepare them for their
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METHODOLOGY Unlike other problem-based laboratories where problem statements are provided, students are not given a particular problem. It is up to them to find one, centered on physical chemistry. This allows them to find a topic that is relevant to them, and they will be motivated to explore. Students in this lab start by searching through the literature for a topic in alignment with their own interests. Students in each group are reading various articles and discussing the content from which they devise a problem on which to work. This approach starts the student in the process of reading and evaluating the literature. It exposes them to numerous topic that they typically may not see. It should be noted that these problems are not always original. In some instances, students are trying to reproduce previously published work. This in itself is a challenge to the students. The material is either new to them or expands on their current knowledge. It requires them to take what they have learned throughout the curriculum and put it into practice. A benefit to this approach is that it is more flexible for students with different levels of preparedness. If a publication from which they are considering is too difficult, they can find something else. Often, the students end up helping each other understand the content of the literature. This is one of the key aspects of cooperative problem-based learning. Because the final product is to be a lab protocol, the students have typically used the Journal of Chemical Education, although some groups have worked from other sources. In either case, students must turn to other sources, additional literature, and/ or their textbooks to assist them in learning. When the students have come up with an experiment, they must perform background work to determine if the experiment is feasible. B
DOI: 10.1021/acs.jchemed.7b00558 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Figure 1. Pictorial representation of the flow of the course. The students start by searching the literature for an experiment that interests them. They perform background work to determine if it is feasible. They present their idea, and the class discusses the experiment and performs the data analysis. Reaching the results typically brings them back to the literature to obtain a better understanding. With an understanding, they present their work via a talk and poster as well as write a lab protocol.
This work includes finding the availability and cost of chemicals and glassware, the safety of the experiment, the ability and availability of the instruments, and a time frame in which to complete the experiment. It is not uncommon for the students to come up with an experiment that requires a chemical or piece of glassware that the school does not possess. In these circumstances, the students must put together an order, including prices and suppliers, of all the materials needed. They are asked to keep any purchases to around $250, although we may allow them to spend more if money is available in the department budget. If the experiment is dangerous or includes toxic chemicals, they must outline a safe experimental approach. The students need to determine if the instrument required for the experiment can do what they require. For example, if their study requires an NMR with the ability to vary temperatures, they need to know if Worcester State’s is equipped to do this. If not, is there another way to do the experiment? All of these aspects require problem solving to some degree and compel the students to critically evaluate how they will implement their experiment. Each group then puts together a presentation that outlines the experiment, its relationship to physical chemistry, the theory behind it, and the question they hope to answer with their work. They provide a list of materials and safety concerns to the class in this presentation. They discuss the concepts that a student performing the experiment should learn. This exercise is intended to not only give them experience with public speaking, but also help them organize their experiments and become familiar with its requirements. Furthermore, they are, in essence, putting together a proposal for their work and then defending it. This is an important aspect of the scientific process that is often not encountered by students until graduate school. After the completion of the presentation, a discussion then takes place. The instructor and the students in the audience will ask questions about the project. The students will usually ask very practical questions about the experimental process. We believe this is attributed to the fact that some of the science is often new to them. However, if the students understand the background theory of the experiment, they will ask questions pertaining to it. The instructor probes the
students on aspects of the experiment that may have been overlooked. This discussion is usually an active process that takes about 30 min. The presenting students often do a good job defending their proposal and addressing the questions. When they do not immediately know the answer to a question, they usually come up with a reasonable response on the spot. We believe this is a very valuable component of this approach. Once the defense of the project is completed, the class is polled in order to determine if the experiment is worth doing. The criteria for moving the experiment forward is based on student interest. If the majority of the students believe they would have enjoyed performing the experiment in Physical Chemistry Lab I, the experiment is allowed to continue. To date, all of the proposed experiments have received favorable feedback. It should be noted that the instructor holds veto power and uses it in instances of excessive cost, safety concerns, or time frame for completing the experiment in the regular lab setting. Typically, students have discussed their selections with the instructor prior to their presentation. This helps to avoid wasting too much time. When an experiment is approved, by show of hands and feedback from the students, the groups write up their experimental procedure. They bring their orders to the lab technician, read the manual and learn how to operate any instrument they are not familiar with, and execute the experiment. After they have collected the data from the experiment, they perform the necessary calculations to get the results. Inevitably the students return to the literature to try and make sense of the data analysis. This simulates a real-life approach to problem solving and keeps the students actively engaged intellectually. Throughout this process the students are only provided guidance, not told what to do. They are allowed to make mistakes and fail. They figure out what they did wrong and try again. They experience the real-life researcher’s frustrations and go through the trial and error process of solving problems. An overview of the process the student go through is illustrated in Figure 1. One of the experiments that students chose to work from is Thermodynamics of DNA Duplex Formation by Howard.32 This experiment uses two complementary DNA oligomers. The first C
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task for the students was to find a company that could make these. They then worked with our lab technician to get the vendor approved by the university and place the order. Additionally, this experiment was performed in the microscale so they had to order cuvettes that were suitable for the experiment. Howard points out that the melting temperature can be determined by computing the first derivative of the absorbance versus temperature curve using graphing software. This required the students to find and learn how to use software that can do this. Another group looked at the photoreduction of benzophenone. In this experiment, the literature gives a well-defined procedure.33,34 However, irradiation times are not provided. The students performing this lab needed to come up with a method to determine irradiation times that would lead to a 10% reduction in benzophenone. On the basis of work from Darensbourg and co-workers,35−38 one group synthesized trans- and cis-tetracarbonylbis(triphenylphospine) tungsten(0) and used group theory to predict the number of peaks that should be observed in an IR spectra. They ran the IR to validate their prediction. This experiment required the use of a Schlenk line that is not part of the typical curriculum. These are several projects that have been undertaken by the students. As stated previously, the first two reflect the situation where the groups are reproducing previously published work while the latter expands on work found in the literature. Students still find reproducing experiments challenging. Often, details are not included because authors in a particular field expect the reader to be familiar with the theory and techniques involved. This is often not the case for students in which they need to learn the prerequisite knowledge of both theory and techniques. This is an intentionally nonstructured course. Although deadlines are provided for the students to complete certain tasks, they find interesting experiments at different times. A lot of the background work leads to experiments that cannot be performed at our institution. Students end up presenting at different times throughout the semester. They are starting and completing laboratories at different times throughout the semester based on the receipt of an order and time to complete the experiment. When there are issues with an instrument, they are required to troubleshoot, in the presence of the instructor, and contact technical support of the instrument’s manufacturer. Even though students frequently pick an experiment that has been published as a physical chemistry experiment within the Journal of Chemical Education, it takes them time to digest the information and fill in gaps that may have been omitted in the original publication. They need to determine the quantities of starting reagents that must be prepared, amount of product they want to acquire, and the number or frequency of data that should be collected, to name a few issues. There are no set due dates for a lab to be completed. We provide them expected completion dates in the syllabus for each experiment. The only set time frame is that both experiments, including presentations and lab protocols, must be completed before the semester ends. Time management becomes an important aspect of what the students are taking away from the course. From our experience, the first experiment typically takes them more than half the semester with only about 6 weeks to complete the second. It takes each group approximately 2 weeks to find an experiment on which they would like to work. It is common for them to be searching and reading the literature throughout the week. Their work is
not limited to the lab period. By the third week they are presenting an outline of the experiment and by week four starting their experiment. The start date depends on receipt of any materials that was ordered. As they are working on their first experiment, it is suggested to them to be looking for a second experiment. Students are sometimes presenting an outline of their second experiment while they are finishing up their first. The time each group has to complete the second experiment is sufficient given that preliminary work, like placing orders, can be done while they are working on their first project. Furthermore, they are familiar with the process and know where to look for information, which suggests that they have acquired some important knowledge. We have considered having them only complete one lab. However, we believe that the second experiment forces them to be more conscientious with time.
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ASSESSMENT
The student’s grade is based on several factors. First is the lab performance and effort throughout the semester. This is based on the instructor’s observations, their weekly journals, and the informal assessments. There was no formal rubric for this portion of the grade. However, in the Spring 2017 semester we ran this course again. This past offering included changes making it slightly different than the previous offering, and therefore, the data is not included in this article. The students in this class were asked to create their own rubric for grading their lab performance. The rubric they decided on is supplied in the Supporting Information. We believe this is a good approach to grading lab performance. They identify how they want to be graded, and we hold them accountable to it. In addition to the oral presentations seeking approval of an experiment, the students pick one of their completed experiments and give an oral presentation on it. This presentation is structured similar to a research presentation, where they introduce the topic, provide a purpose, procedure, data, results, and conclusions. This requires the students to digest all of the information they have obtained and then clearly present it to an audience. During the presentation, questions are asked, and the student’s ability to answer them is noted. The rubric for grading the presentations can be found in the Supporting Information. This rubric is based on Kalpakis which is adapted from work by Brewer and Ebert-May.39 The students also need to create a poster of one of their experiments. They present this at the annual Worcester State undergraduate research symposium. They also present it at a local American Chemical Society poster session if one is geographically accessible. Their lab notebooks are graded according to the rubric in the Supporting Information. They are also required to write a lab protocol which can be used for future students. The lab protocol should be complete. It must include background theory, a list of materials, a thorough procedure, and an explanation of data analysis. We are in the process of creating a rubric for this portion of the grade. The products produced from this lab, forces the students to collate their knowledge and deliver it in a concise and logical manner. They must understand it enough to be able to answer questions and defend their conclusions.
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INSTRUCTOR’S ROLE In this process, the instructor’s job is to be a guide. Prior to running any experiment, the instructor reviews the procedure compiled by the students. As long as there are no safety D
DOI: 10.1021/acs.jchemed.7b00558 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Figure 2. Anonymous survey of the 2015 Physical Chemistry Lab II class. The reported values are an average of the 14 students that reported.
experiments. They take ownership and pride in what they are doing. It is common to find them reading textbooks and additional literature articles in order to make sense of the experiment and their findings. They seek out the guidance of faculty members with knowledge of the subject matter they are studying. It is common to have them working nights, weekends, and over breaks. Because some of the experiments have been adopted by the required Physical Chemistry Lab I course, they strive to get their experiment incorporated into this lab. As a side note, the laboratories that have come out of Lab II and incorporated into Lab I have been looked upon favorably by the students. They enjoy performing these experiments and seem more invested in them. We speculate that this results from the fact that their peers developed the experiments and it is the students themselves that have shaped the lab experience. Furthermore, the frustrated student is often put at ease when they are reminded that it was another student that developed the experiment. There appears to be greater confidence in the Lab I students with regards to completing the experiments. This has been a positive outcome from the format of Lab II on the other students in the chemistry program. The protocols developed by the students in Lab II are not used in Lab I. This is namely because the students in Physical Chemistry Lab I are provided a more concisely written manual that has often had important information removed, forcing them to turn to the literature for answers. The lab protocol written by the Lab II students must be completed so that an assessment of their learning can be made. General comments made by the students report this approach to be beneficial and rewarding. These comments are similar to other findings in problem-based laboratories. They feel that it better prepares them for graduate school and working as a member of a team, to point out a couple of comments made from a 2015 survey. Students also report that
concerns, the group is allowed to proceed whether the procedure has errors or not. Questions posed by the students are responded to with questions. These questions are meant to guide the student in the direction of the answer or to a source that will be helpful to them. The goal of the instructor is to get students to learn on their own, to learn how to find and use sources of information and extract the required material from them. The approach is similar to other nontraditional laboratories, the work environment, and at the graduate level. Although it may appear that the demand on the instructor is minimal, there is a significant time commitment. This again is one of the concerns of nontraditional laboratories. Because this approach is more challenging for the students, we keep an open-door policy for them to stop by anytime for guidance. This results in the students being in the instructor’s office on a regular basis. When issues with instrumentation arise, the instructor needs to be present while the students troubleshoot the problem. Students often ask to come in on weekends, holidays, and work nights. The instructor needs to be present during these times. An obvious issue with this is availability of time and class size. It would be anticipated that this approach would be unmanageable for a large class or if the instructor has other obligations that impact their availability. However, more structure could be incorporated into this model, or the course could be taught by multiple instructors to alleviate these issues. In spite of the workload, the rewards are great. To watch a student work through problems on their own and build their confidence is extremely gratifying.
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FEEDBACK FROM STUDENTS This course has been offered three times. Each time enrollment has increased from 5 in 2011 to 10 and 14 in 2013 and 2015, respectively. From observations made, it was found that this approach led to the students being far more engaged in the E
DOI: 10.1021/acs.jchemed.7b00558 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Figure 3. Educational Testing Services SIRII evaluations results for Category F (Course Outcomes) and the related questions. The results are compared to the comparative mean of 3.75. The + sign indicates that the score is in the 90th percentile.40
were completed. However, SIRII evaluations from the subsequent offering showed an overall better than average result with a score of 4.74+ and 4.60+ compared to the comparative mean of 3.75 for 2015 and 2013, respectively, where the + following the value indicates that the score is in the 90th percentile.40 Furthermore, all of the questions within this category also show reported values greater than the comparative mean. The results are shown in Figure 3. Several of the questions are worth highlighting. First, the results with regards to the first question, “My learning has increased in this course” are 4.77+ and 4.50 for 2015 and 2013, respectively. It is apparent that the students feel they are learning from this style of class. The third category within Question F pertains to interest in the subject matter, “My interest in the subject area has increased”. The values reported for 2015 and 2013 are 4.54 and 4.60, respectively. This is important. As a teacher, we want our students’ interest to increase. We hope that students will leave our classes with a desire to further their education in the topic. The last category in this question which deals with student engagement, “This course actively involved me in what I was learning”, reports a 4.83+ and 4.80+. The students feel that they are actively engaged in their learning. Our Physical Chemistry Lab I is a more traditional lab which is taught by the same instructor as Physical Chemistry Lab II. Furthermore, the students in the elective class would have taken the required lab the previous semester. Although the students taking Lab II are self-selecting, this class does include students with different levels of preparedness, even though a lot of them are stronger students. This makes for a reasonably good (closest) comparison between the traditional and nontraditional laboratories. When comparing the SIRII Category F questions for the same academic years as those presented here for Physical Chemistry Lab II, we see that the new approach scores higher than the traditional approach. The 2014/15 academic year scores are 4.23 and 4.74+ for Lab I and Lab II, respectively, and for the 2012/13 academic year, they are 3.92 and 4.40+. First, we see a notable increase in scores for
their ability to problem solve and read the scientific literature is improved. Some comments from this anonymous class survey follow: “I really liked this lab because it helped me improve problem solving skills and working together with others, rather than running to the professor for help every minute when something goes wrong. I learned to make decision with others as a group even when we all did not agree on everything.” “I thoroughly enjoyed this class. This is how all laboratories (except gen chem lab) should be. For two credits it was a lot of work, but I think this experience will help me greatly in grad school...” “This is a great learning course as it maximizes all the learning you acquire throughout the undergraduate career and apply it in one course...” “The most beneficial class I’ve taken by far” In 2015, the students were also asked to respond to a series of question with a score of 1 to 5; 1 being very little and 5 being very much. These questions and the average of the responses are shown in Figure 2. The majority of these scores are well over 4.00 with only two questions yielding an average of just under 4.00. These two questions correspond to teamwork. It happened that in this year there were a couple of groups of students that did not work well together. These groups were not broken up as these types of situations come up in graduate school and industry so students should be prepared for them. Overall, however, the scores are quite high, >4/5. In essence the students feel that their problem-solving skills have increased, their ability to work with less instructor input has increased, and they feel better prepared to enter graduate school or the workforce. They also prefer this style of lab to the traditional lab style. The standard SIRII evaluations also showed that students look positively on this course. In particular, Category F which deals with course outcomes shows an average value greater than the comparative mean. The first time the course was offered there were only 5 students registered, so no SIRII evaluations F
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From the feedback to date, this approach is looked upon favorably from students. They take ownership of the laboratories they are performing and are more engaged than in traditional laboratories. They improve their problem-solving skills and ability to read the scientific literature. Furthermore, their confidence in their ability to work with minimal instructor input is increased. These are the outcomes we desired from a problem-based approach. These results are anecdotal, however, based on observations and students’ self-reporting through anonymous surveys and SIRII evaluations. Other work, see Tan31 for example, reports similar findings. A more substantive analysis would incorporate formal measurements of the outcomes. For example, once a group has decided on a topic of study, we would write a series of questions on this topic. They will each take the exam/quiz before they start their experiment and then again after. This will help us quantitatively determine to what extent they learned the material. Another assessment might include writing an open-ended question where they are asked how to solve a research-based question where an experiment must be designed. Again, this question would be asked of each student at the beginning and end of the course. This may provide a better assessment of improvement in problem-solving skills. These are two assessment methods we are considering for the future. More work on our part needs to done, however, to explore methods of assessment. This has been applied to a physical chemistry laboratory; however, the approach could be taken in other advanced laboratory settings. In fact, we will be transitioning this into an interdisciplinary lab which will be taught by multiple instructors. This was tried in the Spring 2017 semester where the focus was on physical and inorganic chemistry. Furthermore, students were not allowed to simply reproduce an experiment. At a minimum, they needed to add an additional component to what has been previously published. Student feedback was again positive. In the future, students will work on projects that do not necessarily include physical chemistry topics. For example, the lab may be focused on organic and green chemistry in 2019. The course will be co-taught by faculty with expertise in the subject matter being emphasized. From future offerings of this course, more data needs to be collected to ensure that students are still obtaining the goals of this lab structure. However, in its current format it appeals to the students. They enjoy learning in the problem-based setting and appear to have an increase motivation toward scientific research.
Physical Chemistry Lab I from 2012 to 2014. We believe this is due to the fact that we have shifted the required lab to reflect more of the aspects of the elective course. We have removed the procedures from some of the lab protocols and provided them with the relevant literature papers. This could, however, just be the class. More data is needed to be conclusive. Both of the scores for the Lab II course are in the 90% while the scores for Lab I are in the 80th and 60th percentile for 2014 and 2012 years, respectively. From this data, the student survey, as well as general feedback from the student, we feel that the students are getting a more fulfilling experience that is keeping them engaged. They work with less instructor oversight and refine their problem-solving skills.
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DISCUSSION AND CONCLUSIONS A problem-based approach to teaching an advanced chemistry lab has been presented. In this model, students are exposed to a realistic scientific setting. They select a problem that is interesting to them, increasing their motivation for study. The lab is not content driven. That is, there is no intent to teach a particular topic or experimental technique. At the advanced level, students should have acquired the fundamentals. This lab allows them to refine and build on what they have learned as well as develop crucial problem-solving skills. Furthermore, they are developing their ability to teach themselves. They can explore and study topics that they may not have been exposed to in other courses within the program. They learn this material through self-exploration and group discussions. The instructor serves only as a guide. This approach forces the student to use the current scientific literature to learn. They actively read from multiple journal articles and sometimes textbooks to help them understand a topic. They work from these resources to create experiments and analyze the data. Additionally, this approach introduces them to developing a proposal and defending it. Although it is not a true proposal, it is a good experience for the student. They also are exposed to the necessity of ordering appropriate chemicals and glassware, and learn how to operate unfamiliar instruments. These are important aspects not typically introduced at the undergraduate level. It is difficult to measure exactly how much they take away using this process, and if their problem-solving skills improve; however, it appears to be effective. To what extent it is effective, we cannot conclude currently. The lab protocols provide us some insight into their acquisition of knowledge. The ability to write a lab protocol that effectively explains the background theory, a clear procedure, and a method to perform the data analysis demonstrates, to some level, the ability to synthesize the material. A majority of our students have done a good job at this. Their grades typically range between A and B. Before trying to draw conclusions from the protocols, however, a carefully thought out rubric should be created and provided to the students. This will provide more structure to our expectations from which the students can work. Their ability to present their work in an oral format where they must answer question also gives us an indication of their ability to learn with little guidance. The students have typically done well in this regard (A/B). Although they may not be able to answer every question put to them correctly, they generally try to formulate a reasonable response based on what they know rather than simply replying “I don’t know”. They are essentially problem solving on the spot, which is an outcome that we consider positive.
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ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.7b00558. Sample syllabus (PDF) Rubric for grading oral presentation (PDF) Rubric for grading lab notebooks (PDF) Rubric for grading lab performance (PDF)
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. ORCID
Joseph G. Quattrucci: 0000-0001-7363-7625 G
DOI: 10.1021/acs.jchemed.7b00558 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Notes
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The author declares no competing financial interest.
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DOI: 10.1021/acs.jchemed.7b00558 J. Chem. Educ. XXXX, XXX, XXX−XXX
