Effect of sequenced instruction in introductory mendelian genetics on Piagetian cognitive development in college students

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Authors
Walker, Richard Andrew, 1935-
Advisor
Mertens, Thomas Robert, 1930-
Issue Date
1978
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Thesis (D.Ed.)
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Abstract

In this study, a sequenced, self-"earning guide and a supplementary instructional kit designed to facilitate a student's ability to apply formal operational thought patterns to problems requiring Mendelien genetic analysis were developed and tested. A pre/post-test was designed to test the application of formal operational reasoning patterns and acquired knowledge about Mendelian principles to the solving of problems in genetics. A seven-item, written Piagetian Task Instrument (PTI) containing tasks requiring propositional logic, combinatorial logic, and hypethetico-deductive reasoning was developed and employed to detect cognitive growth toward. the formal operational level. These two instruments were administered in the pre/post-test, format to a control group and to a treatment group, allowing for the testing of the following null hypotheses:Null Hypothesis. 1. There are no significant systematic differences within the classes of the treatment group.Nul1 Hypothesis 2. There are no significant systematic differences within the classes of the control group.Null Hypothesis 3_. There are no statistically significant differences within the classes with regard to sex.Null Hypothesis 4. There are no significant differential effects of the experimental treatment on males and females.Null Hypothesis 5. There is no significant correlation between the content post-test score and th total PTI post-test score. Null Hypothesis 6. There is no significant difference between the adjusted content post-test mean for the treatment group and the adjusted content post-test mean for the control group.Failure to reject null Hypotheses 1, 2, 3, and 4 indicated that there were no systematic differences within the groups with regard to class, meeting time, or sex of the individual. Therefore, each group was statistically treated as a homogenous group. Null Hypothesis 5 was rejected at the .028 level. Since the content post-test referred to in null Hypothesis 5 was determined to be a valid measure of the ability to perform genetic analysis and since the PTI referred to in null Hypothesis 5 was shown to be an effective measure of formal operations, rejection of null Hypothesis 5 indicated that performing genetic analysis requires the application of formal reasoning patterns. Null hypothesis 6 was also rejected. Failure to reject null Hypotheses 1,2, 3, and 4 indicated that the differences between the adjusted content post-test means was the direct result of the instructional treatment. Analysis of the pre/post-test data revealed that those students who received instruction via the sequenced, self-learning materials scored significantly higher (.0001) than did students taught the same material in the traditional manner. Thus, the sequenced instruction developed for the study was effective in increasing student performance on a problem-solving test in Mendelian genetics.The investigation also explored possible relationships between scholastic performance and the ability to perform Piagetian formal operational tasks. The results of this investigation indicated that the ability to perform two of the three elements of Piagetian formal operations is prerequisite to the ability to analyze complex problems in Mendelian genetics. Specifically, the .findings suggested that the higher-order reasoning patterns of propositional logic and combinatorial logic are essential for inductive and deductive analysis of genetic data.An unexpected finding of the study indicated that the ability to perform the formal operation of hypothetico-deductive reasoning is unrelated to problem- solving in Mendelian genetics. However, suice the application of propositional and/or combinatorial logic in the solving of genetics problems also requires consideration of the effects of alternate hypotheses, one may also assume that the ability to perform hypothetico-deductive reasoning is necessary, but, alone, is not sufficient for the ability to apply genetic analysis.The results of the study generated the following major conclusions:1. The written PTI developed for the study is an effective measure of an individual's ability to apply Piagetian formal operations.2. The logical sequencing of self-instructional materials via performance objectives can facilitate the student's ability to apply Piagetian formal operations to genetic analysis.