Research: Science & Education
Numeric and Conceptual Understanding of General Chemistry at a Minority Institution Qun Lin,* Paul Kirsch, and Ralph Turner Florida A&M University, Tallahassee, FL 32307
According to the summary data of 1992, only 1,092 of the 38,814 Ph.D.’s awarded in the USA went to AfricanAmericans. The situation is even worse in the sciences. In the same year, only 17 African-Americans were awarded Ph.D. degrees in chemistry in the USA (1). Considering the growing minority population in the USA, it is imperative that a more effective delivery system be designed to attract more African-Americans into the chemical sciences. Recently, several chemistry educators (2–6) found that a good algorithmic problem solver may have limited understanding of the chemistry behind the algorithmic manipulations and that many bright students who have the ability to study chemistry are not attracted to the area (socalled “second-tier students”). However, most reported results were from a universities with primarily nonminority student populations. Therefore, a study of concept learning versus problem solving at a predominantly minority institution such as Florida A&M University (FAMU) may provide useful information to individuals considering using a more concept-based framework in their teaching. In the present study, we adopted paired questions from Nakhleh’s paper (6). These questions could help to identify the second-tier students in general chemistry classes by studying differential performance on conceptual and algorithmic questions. Each of the five pairs of questions deals with a particular area of general chemistry (gas laws, equations, limiting reagents, empirical formulas, and density). Within each pair, other than algorithmic and conceptual questions, a third questionnaire was added to ask students about their preference for either algorithmic or conceptual problems. During years of teaching in both majority and minority institutions, the authors have observed that a large proportion of minority students are more interested in concepts than in algorithmic aspects of chemistry prob-
Table 1. Frequencies of Response Categories Question Pair
A1
A0
C1
lems. The authors assumed that FAMU students might contain a relatively higher concentration of conceptual thinkers than of algorithmic problem solvers. Other quantitative characteristics were also preliminarily explored. Methods Approximately 270 students enrolled in general chemistry were involved in the study. Standard test scores were provided by FAMU’s Research Council. McNemar’s test, t-test, and frequency analyses were performed by using SAS on a Gateway 486 PC. Results and Discussion The study was incorporated into a general chemistry hour exam. There were only a few missing data. Although the proportion of correct answers is not high, statistically the distribution is normal. The following codes were used in this study: A1: Algorithmic question correct A0: Algorithmic question wrong C1: Conceptual question correct C0: Conceptual question wrong Question pair 1: gas laws Question pair 2: equations Question pair 3: limiting reagents Question pair 4: empirical formulas Question pair 5: density As shown in Table 1, the responses from students were categorized and frequencies were tabulated.
No Differences on Performance McNemar’s test was used to test the significant level of the differences between students’ performance. The probability for significance was set at 0.01. As shown in Table 2, students’ ability to solve the numeric and conceptual problems in question pairs of gas laws and limiting reagents is significantly different. For the rest of the questions, students’ performance on the two types of questions
C0 A1C1 A1C0 A0C1 A0C0
1
103
107
34
176
16
87
18
89
2
92
117
90
119
43
49
47
70
3
37
172
131
78
27
10
104
68
Question Pair
McNemar's χ2
Probability
4
53
156
40
169
20
33
20
136
1
45.3429
