Success on Algorithmic and LOCS vs. Conceptual Chemistry Exam Questions Uri Zoller and Aviva Lubezky Department of Science Education-Chemistry, Haifa University Oranim, Kiryat Tivon 36006, lsrael Mary B. Nakhleh and Barbara Tessier Purdue University, West Lafayette, IN 47906 Yehudit J. Dori Department of Education in Technology and Science, Technion, Israel Institute of Technology, Technion City, Haifa 32000, Israel The Problem, Rationale, and Objectives The prtrvailing- practice at the univ~rriity-lwclteaching of chtmistry conslsts of' levturt~i11).thc professor, follow-
tht!-r~cipclaboratory activities, t,xwciie-solvi~~g recitation sessions. and examinations oriented toward aliorithmic or lower-order cognitive skills (LOCS). The lecture format for instruction is incomnatible with most higher-order cogniand suctive skills (HOCS) ( l j and conceptual learning (2), cess in solving algorithmic nroblems does not indicate mastery of the relevant chemical concepts (3-5). Nonetheless. lecture and al~orithmicLOCSorientation continue to dominate instruction. ~~~~~~
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Two Complementing Trends The acauisition of HOCS bv our students constitutes a major instructional goal i n contemporary chemistry and science teaching. The included capabilities of critical thinking, problem solving, and decision making are considered by many to be the most important learning outcomes of good teaching ( I ) . Thus, two major complementing trends are driving current efforts to reform science education. One trend centers on a belief that the purpose of teaching is the development of students' reasoning and critical thinking ability in the context of the specific content, conceptual frameworks, and processes of science problem-salvingldeeision-makingcapacity, so they can become effective citizens regardless of their role in work and society (6)
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The other trend centers on the belief that our students. mo-
vide memorized answers to LOCS questions. We consider these goals to be the most important learning outcomes to which good teachers should aspire (1, 4). Therefore, we argue that a major purpose of chemical education should be to develop students'capabilities to reason critically and to construct meaningful conceptual frameworks about the concents and urocesses of science,. in general, and chemistry in particular. If these goals can be accom~lished.then students will have a cauacitv of problem solving and'decision making that will enable them-to actually be effective citizens (6).Accordingly, a switch from the current algorithmLOCS emphasis to decision-making, problem-solving, system critical thinking, and conceptual learning i s clearly needed i n chemistry teaching a n d evaluation.
Reasons for Differences in Performance This comparative study focuses on the anticipated differences in students' performance on algorithmic, LOCS, and conceptual exam questions and the correlations between their achievements on these categories across different populations. The objective was not only to determine student performance on these three categories in decreasing order and to explore inter- and intracorrelations, but also to identify possible reasons for these differences. The above is part of our commitment to translate research into appropriate instructional strategies for helping students to develop HOCS and strengthen their conceptual understanding of science. In our present research we wished to explore the relationships between these three categories. W: were also interested in untangling the particular relationshim that mav exist between these constructs. For example,'do LOCS relate to conceptual learning and have little relationship to learning algorithms? Within our ongoing longitudinal study incorporating the HOCS category, further relationships are being explored. For example, are HOCS and LOCS metacognitive skills that might be related to both algorithmic and conceptual learning? Design and Procedures Eight examination questions were constructed and designated as algorithmic, LOCS, conceptual, and HOCS (3,4, 7, 1). Operationally, LOCS and HOCS exam questions (items) are defined a s follows (8).
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LOCS-knowledge questions that require simple recall information or a simple application of known theory or knowledge to familiar situations and context; they can also be problems solvable by means of algorithmic processes that are already known to the salver through specific directions or practice. HOCS-problems unfamiliar to the student that require,for their solution, mare than knowledge application, analysis, and synthesis capabilities, as well as making connections and evaluative thinking on the part of the salver; this includes the application of known theory or knowledge to unfamiliar situations. Algorithmie-questions that require the use of a memorized set of procedures for their solutions. Conceptual~uestionsthat may be text-based or diagrammatic and require students to invoke underlying concepts of the basic theories of science in order to answer the question (34).
The eight questions were placed on either the midterm or final examination a t each university except Purdue, which only used questions 1-3. Therefore, in this paper we report the results related to questions 1-3. The courses in Volume 72 Number 11 November 1995
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Question 1 Ca CL ate tne max m m we gnt of SO, that COL a oe proaLceo from 1.9 mo of oxygen and excess SL f ~ r . 2s + 30, + 2S08
a chi-square test of the differences of the performance means (0-1) within and across the universities on the respective questions nonparametric chi-square correlation tests between the performances on each pair of questions (i.e.,QUQ3, Q2lQ3, and QVQZ)
Question 2 The equation for a reaction is 25 + 302 -,250,. Consider the mixture of sulfur (0) and O2 ( co ) in a closed container as illustrated below:
The results with respect to the HOCS questions a s well as the analysisldiscussion of the interviews with the students conducted a t the Israeli universities will be presented and discussed in a forthcoming paper.. Results and Discussion Means Table 1reveals differences between the means of student achievement on the three categories in each of the universities studied. Table 1. Means of Student Performance on Exam Questions 1-3
Which of the following represents the product mixture?
University
Mean Scores
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Question 1 Question 3 Question 2 LOCS Conceptual Algorithmic Haifa 66 0.88 0.77 0.77 Technion 48 0.98 0.71a 0.4@ 576 Purdue 0.75 0.51 Weighted Mean 'Significantat p < 0.01 based on chi-squaretest.
Question 3 The atomic number of the element magnesium is 12, and its molar mass is 24.3 olmol. The mass numbers of its three natural tsitipes ire 24. 2
