Modern educational theory suggests that the learning of a visual science concept is best taught using a combination of pictorial and verbal instruction describing these characteristics and examples and best evaluated using words and visuals not used during instruction. Recent research suggests a four-step instructional-testing model usable by science teachers. First, teachers should display visual concept examples in an orderly and systematic fashion by beginning with uncomplicated pictured models and proceeding to more complex examples. Second, a few frequently confusing nonexamples should be presented to prevent over-generalization. Third, teachers should present brand new examples and nonexamples. And fourth, teachers should construct test questions preferably containing pictured examples and nonexamples not used during instruction. This model is illustrated by applying it to the teaching of a simple visual concept (the triangle). (Author/BB)