The objectives of the study were: (1) To work out the effect of instructional design on the academic achievement of the students in taxonomic categories of knowledge, comprehension and application. (2) To find out the effect of achievement motivation on students’ academic achievement, knowledge, comprehension and application areas. (3) To study the effect of sex differences on the academic achievement of students in three taxonomic areas. (4) To study the interaction effects of instructional design, achievement motivation and sex on the academic achievement of the students in three taxonomic categories. (5) To study the inter correlation among the variables of instructional design achievement motivation, sex and academic achievement.

The hypothesis of the study were: (1) Academic achievement of students learning through the linear programmed instruction will be better than that of students learning through the adjunct programme. (2) Academic achievement of high achievement motivation group will be significantly better than that of low achievement motivation group. (3) The academic achievement of the students will be significantly different for male and female students in various taxonomic areas. (4) The interaction effect of instructional design, achievement motivation and sex would be significant on the academic achievement in various taxonomic categories. (5) The inter correlation among the variables of instructional design, achievement motivation, sex and academic achievement will be positive and significant.

The sample comprised 240 students of Class IX from Bangkok. The sample was selected using Multi Stage Sampling Method. 

Linear Programmed and Adjunct Programmed Text on Micro – Organism of Biology by Sween, and Achievement Motivation Test by Deo & Mohan were used for data collection. 

The research was Experimental in nature. The researcher used 2×2×2 Factorial Design.

The data were analyzed by ANOVA.

The findings of the study were: (1) The mean gain score of academic achievement of students learning through linear programme is higher in each of the taxonomic categories and also in the total academic achievement than that of the students learning through adjunct programme. (2) The mean score of academic achievement of high achievement motivation group is higher in every taxonomic category and also in the total academic achievement than that of low achievement motivation group. (3) Female students exhibit higher mean score of academic achievement in the areas of knowledge, comprehension and application and also in the total academic achievement than male students. (4) There are significant differences in achievement between the groups of students learning through linear programme and adjunct programme. It is in favour of the group learning through linear programme in comprehension and total academic achievement and no significant differences in areas of knowledge and application. (5) There are significant differences between high achievement motivation and low achievement motivation groups in knowledge, application and total academic achievement and no significant differences exist in area of comprehension. (6) The female students are significantly better than male students in areas of knowledge and total academic achievement and no significant differences are found between two groups in areas of comprehension and application. (7) The treatment effects of the variables of instructional design, achievement motivation and sex on academic achievement in three areas of Bloom’s taxonomic categories are independent of each other. (8) The inter correlations among the variables of instructional design, achievement motivation, sex and academic achievement in Bloom taxonomic categories of knowledge, comprehension, application and total of all taxonomic categories have been concluded in groups . (a) Female students learning through linear programme have positive significant correlation between achievement motivation and academic achievement in knowledge and total academic achievement. (b) Male students learning through linear programme have significant and positive correlation between achievement motivation and academic achievement in knowledge and total academic achievement. (c) Total female and male students learning through linear programme has significant and positive correlation between achievement motivation and academic achievement in knowledge and total academic achievement. (d) Female students learning through adjunct programme have significant and positive correlation between achievement motivation and academic achievement in application and total academic achievement. (e) Male students learning through adjunct programme are not found to have significant correlation between achievement motivation and academic achievement in any area of three taxonomic categories and total academic achievement. (f) Total female and male students learning through adjunct programme exhibit significant and positive correlation between achievement motivation and academic achievement in application and total academic achievement.