Research: Science & Education
Is Laboratory-Based Instruction in Beginning College-Level Chemistry Worth the Effort and Expense? Alexandra Hilosky, Frank Sutman, and Joseph Schmuckler Department of Chemistry, Harcum College, 750 Montgomery Ave., Bryn Mawr, PA 19010
Rationale
ning college-level chemistry instruction in ways that give greater emphasis to laboratory-based experiences.
Overall reform in the teaching of beginning collegelevel chemistry continues to be a primary concern of the Related Literature chemistry community, as indicated by the contents of the A search of the literature related to past research on the monograph published by the Division of Chemical Education role of laboratory-based instruction across the sciences and entitled New Directions for General Chemistry (1) and the for grades 7 through 14 identified more than 600 articles number of presentations related to this issue included in published between 1970 and 1994. Of the 110 reports that the Division of Chemical Education’s program at the 209th are statistically based, only five are directly related to chemannual meeting of the American Chemical Society (2). No istry education at the college level. The remaining articles fewer than nine sections were devoted to this topic, addressreport the results of surveys or are statements of profesing areas such as curriculum reform, instructional resional opinion. sources, molecular modeling, assessing learning, integration The 110 statistically based research reports served as the of computer technology, chemistry for diverse students, and basis for two meta-analyses (6, 7), the results of which will the training and experience of faculty. be reported in a future article. Overall, the meta-analyses Hidden in the total of 60 presentations were two that indicated that across the sciences, inquiry-based laboratory directly addressed reform of the laboratory component of experiences did result in significantly improved cognitive beginning college-level chemistry courses and its role in and noncognitive content learning. This conclusion from the improving overall chemistry instruction and learning. The literature supports the recommendations made in relation two presentations, “The Development and Implementation to the research reported here. of Discovery Based Advances for the Two-Year College Chemistry Curriculum” and “Replacing Lectures with Real Experiences”, emphasized opinions of the authors related The Study Sample to reform in laboratory-based chemistry instruction. Twenty-four chemistry instructors, each responsible for This reporting on research related to the impact of a beginning-level college chemistry course taught in one of laboratory experiences on student learning and attitudes 16 diverse institutions of higher education (IHEs) located seems minimal in light of the level of funding that continues throughout five states in the Northeast region of the United to be available through the National Science Foundation States, made up the study’s teacher population. One addiand the American Chemical Society to develop innovative reformed chemistry courses for the beginning college level. A review of the two earlier mentioned Table 1. Most Frequent Teacher Behaviors and Strategies during reports indicates that many of the funded chemisLaboratory Component of Instruction try “curriculum development projects” have been Occurrence (%) developed without clear indication of reference to Teacher Behavior/Strategy General Introduction the results of research on how laboratory-based Chemistry to Chemistry chemistry instruction presently occurs and the sigSupervises lab work 20.0 25.0 nificant role that laboratory experiences can offer to A s s e s s e s / d i s c u s s e s l a b w o r k 1 4 . 0 7.0 overall chemistry instruction at the beginning colDiscusses procedure 6.7 5.3 lege level. There are several notable exceptions, Praises, comments, or critiques 4.4 8.0 however. For example the “Discovery Chemistry” program at the College of the Holy Cross is deDiscusses theory of experiment 4.0 5.4 signed to guide students to use information derived Performs, assists with procedure 4.0 6.7 from laboratory experiences as the bases for the lecListens while students ask for procedural help 3.1 5.5 ture discussion component of the course (3); and the Leaves lab 3.1 1.3 use of hypercard technology and group instruction G e t s l a b m a t e r i a l 3 . 0 1.5 in the “Cooperative Chemistry” course at Clemson Re-enters lab 2.6 1.3 University involves students in the kinds of openended problems that “real scientists” encounter (4). Suggests/adjusts lab setup 2.6 2.3 We are reporting here on one of a series of studIntegrates lab with theory 2.5 –a ies related to seeking a more effective role for laboAssists with calculations 2.2 –a ratory experiences in science instruction. The study S o c i a l i z e s w i t h s t u d e n t s 2 . 2 2 .0 addressed the status of laboratory-based instruction L i s t e n s w h i l e s t u d e n t s a s k f o r m a t e r i a l s 1 . 9 1 . 0 in chemistry at the beginning college level (5). The a E n g a g e s i n a c a d e m i c a d v i s i n g – 4 . 5 report of this study should be of value to those who a continue to seek effective means of reforming beginNot among behaviors most frequently observed. 100
Journal of Chemical Education • Vol. 75 No. 1 January 1998 • JChemEd.chem.wisc.edu
Research: Science & Education tional IHE located in Germany was included for purposes of comparison because the approach to beginning collegelevel chemistry instruction in Germany was known to differ substantially from that at IHEs across the United States. Three thousand students enrolled in these chemistry courses were included in the study. The 16 IHEs in the United States varied in their admissions practices from very selective to very open. They included private and public IHEs representing two-year and four-year colleges and large universities. The instructors at these IHEs were teaching both traditional and experimental chemistry courses for majors and nonmajors. One experimental course, recently developed through funding by the National Science Foundation and the American Chemical Society, was included among those studied. While the sampling of chemistry courses taught at IHEs in the United States may seem small, our professional backgrounds and experiences indicate that this sample is reasonably typical of the larger population. Only majors in chemistry enrolled in the course taught at the German university. Research Method
to a 15% sample of the 3,000 students enrolled in the chemistry courses (11). An analysis of the printed procedures used by students in carrying out laboratory activities was completed to determine the nature of the chemistry content studied and to surmise the “fit” between these activities and the cognitive levels of development of the enrolled students as determined through use of the IPDT (5). Results
Teaching Behaviors Utilized in Chemistry LaboratoryBased Instruction Table 1 indicates the 15 teaching behaviors or strategies observed most during laboratory instruction in the two types of beginning college level chemistry courses, “Chemistry for Majors” and “Chemistry for Nonmajors”. The data indicate that laboratory instructors in the two types of courses emphasize similar teaching strategies: 13 of the 15 most-used strategies in the course for chemistry majors were also among the top 15 observed in the nonmajor course. This similarity is confirmed by a Wilcoxon ranked correlation coefficient of .8 between the list of most-observed strategies in the two types of chemistry courses. Of these strategies, “supervising students’ laboratory work” occupied most of the time spent in laboratory instruction. Strategies such as “instructors spend laboratory time asking students to explain their observations using chemical theory” or the “instructors listen to students’ explanation” were infrequently used. Totally missing in both courses is “instructors assess student learning that develops directly from laboratory experiences”. “Instructors use computers and other technological tool” was seldom used. Examination of Table 1 indicates that the most frequently observed teaching strategies are not designed to develop
Direct observations and videotaping of instruction during 24 prelab, postlab, and actual chemistry laboratory sessions were made. The instruction was analyzed using a validated modified-revised version of Vickery’s original 1970 Science Teacher Behavior Inventory (STBI). The original version of the STBI was validated by a panel of experts (8). The modified-revised version or MR-STBI was also validated by a panel of 3 specialists who took into account a definition for and descriptions of what constitutes construct validity of assessment instruments as described in Technical Issues in Large Scale Performance Assessment (9). The MR-STBI is designed to categorize teaching behaviors or strategies that Table 2. Least Frequent Teacher Behaviors and Strategies during Laboratory occur during laboratory instruction across Component of Instruction the sciences, including chemistry. For exOccurrence (%) ample, it includes “the instructor: directly supervises laboratory work; assists with Teacher Behavior/Strategy General Introduction math calculation, explains laboratory Chemistry to Chemistry findings, in terms of (chemical) theory; Adjusts students' science misconcepts 0 0 questions students; and responds to pro- Accepts students' idea on procedure 0 0 cedural questions”. It also includes teachAsks students to place data on board for class discussion 0 –a ing strategies that are emphasized in the 0 0 National Science Education Standards Uses students' idea in lab collection procedures 0 0 (10). These, for example, relate to giving Questions students' procedure emphasis to inquiry based instruction Listens while students comment on discipline 0 0 and the use of technology during labora- Assists students using concrete models/technical support 0.03 0 tory experiences. All researchers who Questions students on hypothesis or misconception 0.05 0 used the MR-STBI in categorizing and Helps with prelab work 0.05 0 analyzing laboratory instruction were 0.05 0 trained in its use and inter-rater reliabil- Writes problem solution on board P r e p a r e s c l a s s i n s t r u m e n t s 0 . 0 6 –a ity was determined. Each instructor whose teaching was Administers lab quiz 0.07 –a observed and videotaped was interviewed Assigns job to students 0.08 0 using an ethnographically constructed Listens while students explain science concepts 0.43 –a survey instrument validated by a panel of Questions students regarding results –a 0 3 experts. This instrument was designed 0 –a to elicit information that might explain Assists with calculations a G r a d e s s t u d e n t s ' p r e s e n c e – 0 why certain teaching strategies were or a were not emphasized during the analyzed Instructs students using instruments – 0.25 chemistry laboratory instruction. Sits at desk consulting students –a 0.28 The “Inventory of Piagetian Developa Not among behaviors least frequently observed. mental Tasks” (IPDT) was administered JChemEd.chem.wisc.edu • Vol. 75 No. 1 January 1998 • Journal of Chemical Education
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Research: Science & Education higher-order thinking processes. In contrast, Table 2 indicates the teaching strategies that were emphasized the least. These infrequently used teaching strategies are those designed to develop higher order thinking processes through instruction. The results of the ethnographically constructed interviews of faculty in the United States indicate that their plans did not include addressing further the data collected from the results of the laboratory experiences. Plans to include computer and other technological tools were not mentioned. Nor were there plans to assess, through future examinations, the learning that occurred as a result of laboratory experiences. It is clear that, in their planning for laboratory instruction, these faculty did not consider the potential contribution of this instruction to developing higher-order thinking. Rather, they supported inclusion of “the laboratory” mainly because historically it has been a significant component of chemistry instruction. The data collected through use of the IPDT indicate that 49% of the U.S. students enrolled in the courses for majors and 15% of those enrolled in the nonmajor courses thought at the highest formal cognitive level, whereas 100% of German students thought at this high level.
Table 3. Laboratory Activities Observed and Analyzed Course Title of Activity Type a
Classification of Content
NM
Analysis of Byproducts of Smoking
M
The Gravimetric Determination of SO4
IHLM
Traditional
NM
Gas Laws
IHLM
Traditional
M
Electrolysis
IHLM
Traditional
M
Titration
HO
Traditional
M
Acid/Base/Buffer
IHLM
Modern
Modern
Modern
NM
Synthesis of Nylon
IHLM
M
Kinetics/Thermodynamics
HO
Traditional
M
Kinetics/Rate Reactions
IHLM
Traditional
M
Analysis of an Inorganic Compound
CM L
Traditional
M
Qualitative Analysis
IHLM
Traditional
NM
Reactions of Proteins
CL M
Modern
M
Stoichiometry: Reaction of Mg + HCl
CLM
Traditional
NM
Gas Laws
CLM
Traditional
M
Thin-Layer Chromatography
IHLM
Modern
M
Thin-Layer Chromatography
IHLM
Modern
M
Quantitative Analysis
IHLM
Traditional
M
Gas Chromatography
IHLM
Traditional
M
Spectroscopic Analysis of Metals
IHLM
Traditional
M
Solubility and Thermodynamics
IHLM
Traditional
M
Gas Chromatography
IHLM
Traditional
M
Kinetics/Equilibrium
CL M
Traditional
a
NM = chemistry for nonmajors; M = chemistry for majors. CLM = commercial laboratory manual; IHLM = inhouse laboratory manual; HO = handout prepared by faculty member. b
The Fit between Instructors’ Expectations and Students’ Cognitive Levels Table 3 indicates the titles of the laboratory experiments carried out in both types of chemistry courses offered at IHEs within the United States. Although about 30% of these experiments address fairly nontraditional content, in no instance did the directions offer students opportunity to develop or revise laboratory procedures or to seek available procedures from other sources. In almost every case the directions called upon students to record data by using fillin-the-blank forms. This procedure is in opposition to the recommendation that “students learn to write their own laboratory outcomes” (New Directions for General Chemistry [1]). Instead, the “guides” directed students to (i) read the directions for carrying out the “experiments” and answer a set of preliminary questions, (ii) follow and carry out the stated procedures, (iii) make observations and record the data related to these observations in the tear-out forms, and (iv) answer specific questions based on the recorded data. In every instance the instructors left it totally to students to address these questions and to include answers as part of the laboratory report. The nature of the questions is such that to answer them effectively requires already developed observational skills and the ability to manipulate data mathematically or to be competent in using a calculator for this purpose. It also requires that students be able to maintain careful records of observations and to think at the formal operational cognitive level. Instructors did not consider it their responsibility to develop these skills, yet they mentioned that most students lacked them. 102
Source of Directions Used b IHLM
In all but one of the 24 observed laboratory sessions in the United States, the many procedural questions asked by students were directly answered verbally by the laboratory instructors. In the one exception students were referred back to the written directions. This procedure was followed after students had been assigned to read and understand the written directions ahead of time. Apparently the laboratory instructors believed that it was their role to serve as the verbal source of procedural help. There was little opportunity for students to develop habits that would sustain self-motivated learning. In nearly every instance, laboratory reports were assessed or graded holistically on a scale of 1–10, using the following criteria: (i) the overall completeness of the report (i.e., the number of questions answered); (ii) evidence that the student was present to conduct the experiment; and (iii) percent yield or percent error. The grades received for laboratory experiences were considered minimally, if at all, in determining final course grades. It would seem that these practices would diminish the value that students place on laboratory-based experiences. Beginning chemistry laboratory-based instruction in the German university emphasized very traditional wetbench analytical chemistry. However, instead of being supplied with written directions, students were expected to seek these directions from the literature or they were expected, in groups, to design the procedures to be followed. This was without constant support from the laboratory instructor. In the process, students also sought references that supplied them with the chemical theory that could be used to explain
Journal of Chemical Education • Vol. 75 No. 1 January 1998 • JChemEd.chem.wisc.edu
Research: Science & Education
Table 4. Comparison of Laboratory Instruction in U.S. and German IHEs 16 U.S. IHEs
German IHE
Instructor nearly always present Activities specifically directed and controlled by the instructor Students overly dependent on instructor on procedural matters Course not laboratory driven
Instructor seldom present Activities planned for and directed by students Student overly independent of instructor on procedural matters Course laboratory driven
Analytical instrumentation used
No use of analytical instrumentation
Some use of computer technology Student often interact with instructor concerning procedures to be followed Logic and thinking not individually addressed by instructor
No use of computer technology Students often interact with instructor in discussion of theory Logic and thinking individually addressed by instructor
their recorded observations. It was understood that through oral examination they would be asked not only to describe what they observed but also to supply the related chemical theory. The primary responsibility of the laboratory overseer is to develop students’ self-reliance and reliance on one another as members of a team in carrying out investigations. In addition, the expectation is that students will (i) clearly record the procedures (in a bound laboratory notebook), (ii) carefully carry out these procedures, (iii) think through and interpret the experimental results, (iv) draw conclusions and record them, and (v) present a complete record of the investigation to the overseer for review and comment. The final oral examination of understandings from the laboratory experiences, conducted by the department head and the overseer, begins with a discussion of the procedure and the results of the investigation. Throughout the examination each student is asked to explain the observed phenomena using chemical theory. Students may refer to their laboratory record in this process. It is clear that the laboratory experience, including the oral assessment, offers students opportunity to call upon higher-order thought processes and to further develop and refine both these skills and the ability to practice self-motivated learning. The German students voiced concern that the beginning laboratory experiences do not include the use of computers or modern laboratory instrumentation. This concern related directly to the observation of instruction and its analysis, using the MR-STBI, that technology played no role in the instruction. The faculty explained this by stating that they to not consider the development of these technology skills to be a primary objective of the beginning chemistry course. Table 4 summarizes, for comparison, the major characteristics emphasized in instruction in both types of beginning college level chemistry at IHEs in the United States and at the single IHE in Germany. Implications of the Study Laboratory experiences in chemistry at the beginning college level in the United States generally do not serve as the basis or driving force for follow-up instruction. Rather, these experiences are self contained. They emphasize verifying already established conclusions. At best, they develop learning that does not correlate with material presented in
future instructional sessions. This condition continues to exist in the newer experimental chemistry courses despite the fact that chemists and chemical educators have indicated the essential nature of laboratory experiences in the overall process of learning. The science education literature in the United States overwhelmingly deplores the so-called cookbook approach to laboratory-based instruction. To most professional educators, “cookbook” means following detailed printed directions. For the most part, college students enrolled in beginning chemistry courses do not, during laboratory-based experiences, learn to follow directions. Instead, they learn to depend excessively upon oral directions presented by the instructor in response to their queries. While the literature belittles cookbook-oriented laboratory experiences, we propose that, in appropriate contexts, following directions designed by others is an integral component of the scientific process. However, it should be learned and used within the context of follow-up inquiry. As practiced now, following directions occupies much of the laboratory experience, leaving little time either during laboratory sessions or afterward for students to become engaged in discussions and other instructional strategies that lead to development of higherorder thinking—a skill that the literature proposes is so essential to the well-being of our technologically based society. From this study, which includes an analysis of teaching in one “reformed” course in beginning college-level chemistry, it seems reasonable to recommend the following changes in instruction in these courses. •
• •
•
•
Reduce the number of investigations within a given course and provide more flexibility in the availability of laboratory space and materials for student use. Utilize laboratory experiences to drive further instruction. Train (or retrain) laboratory instructors to serve more as facilitators who assist students in developing their own plans or obtaining other appropriate procedures for determining outcomes from laboratory experiences. Redesign procedures for assessing student learning in college-level chemistry courses to take into account major objectives for use of laboratory-based experiences. Impress upon laboratory instructors that designing laboratory experiences around more recently developed chemistry content, in itself, does not insure that their approach to instruction has been reformed.
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1. Task Force on the General Chemistry Curriculum, National Science Foundation. New Directions for General Chemistry: A Resource for Curricular Change; Division of Chemical Education, 1994. 2. Pine, S. Chem. Eng. News 1995, March, 139. 3. Ricci, R.; Ditzer, M. J. Chem. Educ. 1991, 68, 228–231. 4. Cooper, M. Cooperative Chemistry Laboratory Manual; McGraw-Hill: New York, 1992. 5. Hilosky, A. Profile of Instructional Practices in Beginning Level Chemistry Laboratory Experiences: Seeking a More Effective Role for LaboratoryBased Instruction; Ph.D. Dissertation, Temple University, Philadelphia, PA, 1995; Dissert. Abstr. Oct 1995, A-56/04, p 1303, AAC 9527488. 6. Zhou, M. A Detailed Meta-Analysis of the Effects of Laboratory-Based Secondary School Level Science Instruction on Student Learning; Ph.D. Dissertation, Temple University, Philadelphia, PA, 1995; Dissert. Abstr. Oct 1995, A-56/04, p 1237, AAC 9527552. 7. Rubin, S. Evaluation and Meta-Analysis of Selected Research Related to Laboratory-Based Beginning College Science Instruction of Student Learning; Ph.D. Dissertation, Temple University, Philadelphia, PA, 1996; Dissert. Abstr. Sept 1996, A-57/03, p 1087, AAC 9623799. 8. Vickery, R. An Examination of Possible Changes of Certain Aspects of Teacher Behavior Resulting from Adoption of Individualized Laboratory Centered Instructional Materials. Ph.D. dissertation, Florida State University, Tallahassee, 1968. 9. Technical Issues in Large Scale Assessment; National Center for Educational Statistics, U.S. Dept. of Education: Washington, DC, 1996. 10. National Research Council. National Science Education Standards; National Academy Press: Washington, DC, 1996. 11. Furth, H. An Inventory of Piaget’s Developmental Tasks; Catholic University, Department of Psychology, Center for Research in Thinking and Language: Washington, DC, 1970.
104 Procedures described and data reported in a record book, followed by a summary developed by using word processing. Safe and quiet, to include comfortable areas that can be used for effective planning, discussion, and thinking. 75% Supplies, equipment, and computers. Independent thinkers who have developed skills essential to the working world as well as to success in further study. Greater respect for chemistry. Laboratory driven.
Emphasis on constructivist learning theory and inquiry. Procedures described and data reported in a record book, followed by a summary developed by using word processing. Safe and quiet, to include comfortable areas for use in effective planning, discussion, and thinking. 75%
Journal of Chemical Education • Vol. 75 No. 1 January 1998 • JChemEd.chem.wisc.edu Supplies, electronic analytical equipment, and computers Increased independent thinking, better prepared for advanced inquiry type investigations and further study in the sciences or allied fields. Greater respect for chemistry. Laboratory driven.
Overall structure
Outcomes
Lab equipment and supplies
Weight on total final grade
Environment
Nature of report on procedures and results
Emphasis on constructivist learning theory and inquiry.
Class discussions and presentations of results.
Instructional strategies
Read directions, followed by planning period during which the computer is used to inform about procedural matter. Class discussions and presentation of results.
Determine increase in knowledge and skill development; ability to follow directions, seek out appropriate references, and reflect on processes and outcomes; changes in attitude and ability to report results to others. Oral, written, and practical (hands-on) examinations.
Follow directions, design group plans, think–hypothesize, perform procedures, interpret results and present for investigative-type review. 5–6 direction-oriented, followed by 8–10 extensive investigations
Plan, design, think–hypothesize, perform procedures, interpret and present through team projects. 4–5 highly directed, followed by 10–12 investigations for which directions are sought or developed. Determine increase in knowledge and manipulative skill development; effectiveness of plans; accuracy and efficiency of decisions and judgment; quality of reports and project presentations. Oral and practical (hands-on) examinations and analyses of written reports. Planning period using computer for background search.
For a short period working in class, then in teams of 4 or 5.
Initially assumes students must be taught to follow directions and to be involved in directed inquiry; this followed by serving as team leader and manager of safety. Manager to assure safety. Learns quickly to follow directions and seek out references. This is followed by team membership and taking more responsibility for own learning. Working first in pairs, then in teams of 4 or 5 members
Assignments: post-lab
Assignments: pre-lab
Methods of assessment
Assessment of learning
Nature of activities and number to be completed per academic year
Tasks
Student grouping
Role of student
Role of instructor
Introduction to Chemistry (Nonmajors)
Calls for students to read and follow directions and seek appropriate references; serves as team leader developing students' abilities to take responsibility for their own learning. Manager to assure safety. Active team member, responsible for own learning.
Table 5. Recommended Formats for Reform in College Chemistry Courses
Literature Cited
General Chemistry (Majors)
Table 5 is derived from both our findings from the study and our professional experiences. These recommendations take into account the cognitive level of development of the majority of students that enroll in these courses. The recommended formats can guide laboratory instructors as they plan action to reform this component of chemistry courses. We propose that only through such reform will chemistry faculty and others be able to conclude that laboratory experiences are worth both the required effort and cost.
Characteristic
Research: Science & Education
