This document discusses different types of educational materials including board games, sound filmstrips, tape-text programs, and radio-vision programs. It provides the purposes of these materials such as using sound filmstrips for phonics and narration, and radio-vision programs to enhance understanding from radio commentaries. The strengths and weaknesses of each material are also outlined, for example board games can encourage problem solving but teachers have less control, while sound filmstrips make learning visual but the devices may be outdated.