- Edgar Dale devised the Cone of Experience in 1946 which proposed that learning is most effective when it progresses from abstract to concrete.
- Jerome Bruner is an American psychologist who contributed significantly to cognitive psychology and learning theory through proposing a three-fold analysis of learning styles - enactive, iconic, and symbolic.
- Educational media like pictures, photographs, illustrations and flashcards can be used at different levels - enumerative, descriptive, interpretative, and integrative - to concretize words and concepts for learners.