EFFECTS OF INSTRUCTIONAL MATERIALS ON ACHIEVEMENT AND RETENTION OF BIOLOGY CONCEPTS AMONG SECONDARY SCHOOL STUDENTS IN IMO STATE, NIGERIA
Instructional materials are materials which assist teachers to make their lessons explicit to learners. They are used to transmit information, ideas and notes to learners (Ijaduala 1997).Usman and Adewumi (2006) state that instructional materials can be referred to as the widely variety of equipment and materials used for teaching/learning by teachers to stimulate self-activity on the part of the pupils. Instructional materials include both visual and audio-visual equipments. Visual equipments are those materials that you see. These include; flashcards, posters, charts, textbooks, real objects, models, chalkboard, and so on. While Audio-visual materials are those materials that stimulate both the visual (sight) and audio (hearing) senses. Examples are; computers, tape recorder, radios, videos, televisions among others. Their importance in the teaching/ learning process is not to be over-emphasized. Brown (2000) summarized the role of instructional materials as follows: a. It promotes meaningful communication, hence effective learning b. It ensures retention, thus making learning more permanent. c. It helps to overcome the limitation of classroom by making the inaccessible accessible, This is especially true of films, filmstrips and so on d. They provide a common experience upon which other learning can be developed. They stimulate and motivate students to learn.