Selected Variables As Predictors of Achievement In General Biology Courses at Xavier University of Louisiana (Black)

Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)


Chemistry and Biochemistry

First Advisor

Donald R. Cotten

Advisor Department

Chemistry and Biochemistry


This study was designed to determine the relationship between selected independent variables and grades in a general biology sequence (Biology 1230-1240) at Xavier University of Louisiana. The predictor variables were: High School Grade-Point Average, ACT scores--Composite, English, Mathematics, Social Studies, and Natural Science--Nelson-Denny Reading Test total score, sex, student classification, and Biology 1230 grade, used as a predictor variable only when the criterion variable was Biology 1240 grade. The study was limited to those students who entered a biomedical science program at the university in the fall of 1981. Data on 120 students in the Biology 1230 sample and 82 students of the Biology 1240 sample were analyzed by multiple regression programs from the Statistical Package of the Social Sciences to formulate predictive equations for predicting grades in general biology. The results indicated that (1) The entire predictor list was a valid predictor of performance in general biology, accounting for 41% of the variance in biology grade, (2) Equations less complex than the full models were valid predictors of grades in general biology, (3) Separate equations are needed for predicting Biology 1230 grade for freshmen and sophomores, and (4) ACT subtest scores need not be included as predictors if the ACT Composite score is also being used as an independent variable. The findings of the study seem to warrant the following conclusions: (1) A combination of ACT Composite score and HSGPA can be used to predict Biology 1230 grade for freshmen, (2) ACT Composite score can be used to predict Biology 1230 grade for sophomores, and (3) A combination of Biology 1230 grade, HSGPA, and ACT Composite score can be used to predict Biology 1240 grade. These predictors could be used to counsel students who enter biomedical science programs at Xavier University.