In the Laboratory
Addition of a Project-Based Component W to a Conventional Expository Physical Chemistry Laboratory Georgios Tsaparlis* and Marianna Gorezi Department of Chemistry, University of Ioannina, GR-451 10 Ioannina, Greece; *
[email protected] Laboratory work is widely accepted as essential for training chemists at universities. Its aims are to encourage students to gain manipulative skills, observational skills, ability to interpret experimental data, and ability to plan experiments (1). To this must be added affective aims such as interest in the subject, enjoyment of the subject, and a feeling of reality for the phenomena talked about in theory (2). Domin (3) distinguishes four types of laboratory instruction: expository, inquiry, discovery, and problem-based. These styles can be differentiated by their outcome, their approach, and their procedure. The outcome of any laboratory activity is either predetermined or undetermined. Expository and problem-based activities typically follow a deductive approach, while discovery and inquiry activities are inductive. The most commonly applied style of laboratory instruction is the expository one, which is instructor-centered. The student has only to follow the instructor’s instructions or the procedure (from the manual). The outcome is predetermined and may also be already known to the student. This laboratory satisfies the need to minimize resources, particularly time, space, equipment, and personnel (4). Despite this efficiency, expository instruction has been criticized for placing little emphasis on thinking (5, 6). Its “cookbook” nature emphasizes the mechanical following of specific procedures to collect data, to verify or demonstrate principles described in textbooks. In this way, it is an ineffective means of building concepts and unrealistic in its portrayal of scientific experimentation (7), while little meaningful learning may take place (8). Such laboratory experiences facilitate the development of lower-order cognitive skills, such as rote learning and algorithmic problem solving (9). In addition, they “have little relevance to real life and so fail to promote in students a genuine interest and motivation for practical work” (7).
List 1. Tasks Assigned to the Students as Project Work 1. Solvent–ion interactions in salt water (10). 2. Graphical presentation of the Born–Haber cycle for estimating the electrode potentials of metals (11). 3. An undergraduate physical chemistry experiment on surfactants: electrochemical study of a commercial soap (12). 4. The solubility product of PbCl2 from electrochemical measurements (13). 5. Electrochemistry of the zinc–silver oxide system (14). 6. Lithium batteries: A practical application of chemical principles (15). 7. The hydrogen electrode (16). 8. A demonstration of corrosion by differential aeration (17). NOTE: The order of the projects is in accordance with the order of the oral presentations by the students in the final seminar (see text).
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Project–Based Laboratory Work Accepting the skepticism about the conventional expository laboratory and acknowledging that it is not an easy task to replace it entirely with inquiry-type work, we propose a modification of a conventional expository physical chemistry laboratory to accommodate a project-based component.1 The proposed activities are not of the inquiry type because their outcome is predetermined and the students do not have to generate their own procedures; that is, actually, there is no open-endedness. On the other hand, the activities have many of the other features of inquiry-type work: they are more student-centered, contain less direction, and give the student more responsibility as well as ownership of the laboratory activity. A study was carried out with third-year, fifth-semester, undergraduate chemistry students as part of a compulsory practical course in physical chemistry. Students working collaboratively carried out both the conventional and the project parts: in pairs for the conventional experiments and in groups of four for the project work. In the proposed approach, the conventional component remained intact, simply being enriched with the project-based component. Each week, two pairs of students, instead of having to carry out a conventional experiment, had to start their project work. They met with the two instructors (the authors of this article), who assigned them a project, taken from chemical literature. A total of eight projects were assigned, of which seven were taken from articles in this Journal. A list of the projects is given in List 1. During the first meeting, the instructors gave the students detailed instructions about the aims and objectives, how to work, what further literature sources to use, and so forth. During subsequent laboratory sessions, the students had to meet regularly with the instructors, to report their progress and ask further advice. The last session in the laboratory was devoted to carrying out the experiments arising from their projects. During the previous week, students worked in collaboration with the senior instructor, the laboratory technician, and other members of the chemistry department to get necessary materials and equipment. Owing to a lack of general stores in the department, this was not an easy task. The instructors were very uncertain about the outcome of the experiments, fearing that chaos would prevail in the laboratory. The outcome was totally the reverse. Students were dedicated, patient, and enthusiastic. Even the laboratory technician was more dedicated, patient, and helpful. A pair of students, asked by the professor about the unusual atmosphere, commented that this was because the projects were original for them and that a feeling of ownership was there. The concluding, and important, part of the project was the written report (one for each group of 4) and the public oral presentation of the projects by the students during a special seminar. All four students in each group had to contribute to the
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presentation. Students need guidance from the instructors with the oral and visual presentation. Evauation by the Students An evaluation of the new approach was carried out through a written questionnaire during the final seminar. A total of 27 completed questionnaires were collected from the students: 17 from female and 10 from male students. The evaluation showed that the majority of the students (93%) were in favor of collaborative work. Working in groups of four seemed acceptable to most (89%). Asked if they were happy with their particular project work, students were divided between positive (52%) and neutral (48%). Some reasons for neutral answers were “not sufficient time”, “not interesting subject”, “not satisfactory presentation”, “difficulty in cooperation”, “lack of experimental data”, and “work overload”. The unequal contribution of the members of the group was reported by 30% of the students as the most serious problem of working in groups. This finding is in accordance with the findings of previous work that, while most students enjoy the social interaction of group work, many are not yet functioning efficiently as team members (18); further, some students seem to prefer individual learning (19). Bodner et al. (20) commented that an instructional intervention that is beneficial to some students is likely to be harmful to some other students. Knowledge of students’ personality trends can be useful in the proper composition of the groups (21). Thus, social students are expected to prefer to engage in group activities, while conscientious students have a preference for a well-organized learning environment such as that of the conventional expository laboratory. On the other hand, curious students prefer to engage actively in their educational process through various activities (for example, discovery learning), while they do not like to be passive receivers or listeners. The situation with students who are achievers may vary: some may prefer to work on their own, while others may find group work as also suitable to them. The difficulties encountered by the students in executing the project work were low to moderate. The students rated the main factors of difficulty as follows on a 0–4 scale, with 4 representing very high difficulty: literature in English (1.8), laboratory facilities (1.7), presentation of work in public (1.4), application of laboratory techniques (1.4), and collaboration with the other members of the group (1.3). Finally, a number of suggestions were made for improving collaborative project work in connection with teaching of laboratory courses, with the following being most interesting: free choice of subject, fully equipped laboratory, more references and bibliography provided by the instructor, more direct cooperation with the instructor, more than just one project, more time available, and more contemporary topics.
Preference for the Various Projects Used Students were asked to state which of the remaining projects (apart from their own one) they liked most (they could select up to 2 projects). The connection of chemistry with everyday life, especially modern applications such as the lithium batteries (frequency: 13/27), the corrosion of metals (10/27), and commercial soaps (7/27), attracted the interest and attention of the students. This finding is in accord with those of Teixeira–Dias et al. (22) and of Belt et al. (23). www.JCE.DivCHED.org
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Project versus Conventional Practical Work The questionnaire elicited a comparison between project practical work and conventional expository laboratory for development of various abilities. Project work was judged superior ( p < 0.05) for the following ten abilities (in descending order): (i) familiarization with English literature, (ii) searching for literature, (iii) training for public presentations, (iv) writing a scientific text, (v) connecting theory with modern scientific reality, (vi) taking initiative, (vii) personal self-image, (viii) motive for learning, (ix) stating objectives, and (x) critical thinking. Abilities i–iv and vi are communication skills, while ability vii relates to personality and abilities viii– x relate to the psychology of learning. All other abilities for which differences were not revealed are equally supported by both approaches, for instance: ability to handle instruments and equipment, connection of theory with practice (applications), observation, experience in approaching of theoretical and practical problems, evaluation of experimental results, and data treatment or processing. Importance of the Different Stages of a Successful Experimental Procedure Students were asked to assess the importance of each stage of the two alternative procedures to the success of the whole experiment. The presentation and the prelaboratory preparation were clearly more important in the case of the project work. Execution of the experiment in the laboratory as well as data treatment and processing were equally important for both the conventional laboratory and project work. Conclusion and Implications The proposed modification of a conventional expository physical chemistry laboratory to accommodate a project-based component can be a success, overcoming many of the serious problems that are widely recognized to characterize and undermine the conventional laboratory. The originality of the projects and the feeling of ownership and responsibility contributed to the dedication and enthusiasm of the students during the performance of the experiments. Many arguments from the science education literature support the proposed methodology (24–27). Piagetian personal constructivism, and Vygotskian social-cultural constructivism are of great relevance. According to Vygotsky (28), the learner actively constructs his or her knowledge, but this process is greatly assisted by interactions with peers and with the teacher who acts at the learners’ zone of proximal development. Laboratory tasks should “have within them the elements of motivation that stem from confidence in and a sense of ownership of the activity by the student” (29). Also “motivation is not guaranteed by simply doing practical work; we need to provide interesting and exciting experiments, and allow learners a measure of self-directed investigation” (30). Expository-type laboratory activities will continue to be needed for the development of basic experimental skills of the students, despite their inefficiency in providing a realistic scientific environment and in promoting the use of higher-order cognitive skills (31, 32). Even defenders of the conventional type of laboratory and lab manual do not claim that they are always wisely used, nor do they claim that they should be used exclusively (33). However, the dominant problem is that “despite significant studies in the literature establishing the effec-
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tiveness of inquiry labs in comparison with verification labs, the use and dissemination of cookbook labs is still prevalent in many high school and college institutions” (34). We agree with Byers (18) that “project work may encourage deeper thinking about experiments before they are carried out and deeper reflection on the results than is usually found with recipe-following procedures”. Needless to add that to be effective, project work of the type described here must be extended to all practical courses, but also to the theoretical courses throughout a chemistry degree program. Last but not least, we subscribe to the conviction of 11 U.S. academics and scientists, published in Science magazine, that time has come for “scientific teaching” to be used in universities, “in which teaching is approached with the same rigor as science at its best. ... Scientific teaching involves active learning strategies to engage students in the process of science and teaching methods that have been systematically tested and shown to reach diverse students” (35). W
Supplemental Material
The complete article including detailed data from the student questionnaire, the effect of students’ learning beliefs, and a discussion about the group size and the dynamics within the group are available in this issue of JCE Online. Note 1. An earlier version of the full article has been published elsewhere (36).
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