Abstract
The purpose of the study was to determine the effect of instructional models on achievement of Biology concepts the digestive system among secondary school students. To achieve the purpose of the study, a research question was raised and one hypothesis formulated to guide it. Empirical review was in line with the variables of the study. The population of the study comprised all the SS II Biology students in the 88 public secondary school in Ogoja education zone. The research design adopted for the study is a quasi-experimental non-randomized factorial design using a pretest-posttest control group for the study. A Biology achievement test with 50 items multiple choice questions was the instrument for data collection, administered to 125 senior secondary school two Biology students. The reliability of the instrument was obtained at 0.79 using Kuder Richardson Formula (KR-20). Analysis of covariance was used and the result showed that students taught Biology concepts using instructional models had a higher mean score than those taught without instructional models. Biology teachers should incorporate instructional models as a key component in the teaching-learning process.
Keywords: Instructional Model, Achievement, Retention, Biology, Secondary School