This comes directly from a 500-page tome on cognitive psychology research called Graphics for Learning by Ruth Colvin Clark and Chopeta Lyons. Ruth Colvin Clark, in particular, has worked with John Sweller and Richard Mayer, both luminaries belatedly discovered by the current generation of teachers.

When visuals are not merely decorative or entertaining, they can draw attention to important elements in an instructional guide, avoiding the burden of a split, or divided attention. 

HOW2s achieve this by eliminating any extraneous detail like classroom furniture and, even, characteristics of the students’ age, race or sex. Essential procedural information comes to the fore by the use of clear step-by-step visuals, made obvious by numbering and arrows.

By providing a visual overview of the process, visuals help trigger recognition and anticipate future content. This merging of past and future imagery helps connect to prior learning and assimilate future information.

HOW2s’ consistent use of procedural, step-by-step, graphics help teachers recognise the format, and this aids them to connect to both their prior experiences of teaching, as well as their knowledge of previously studied HOW2s.

Equally powerful is their ability to promote the teacher to imagine walking through the teaching sequence. This visceral reading of the HOW2s adds an important personalised feeling to the learning process.

Cognitive load is when working memory is overloaded and cannot process any more incoming information. For this reason, photographs and videos can often be counterproductive. And why simple line drawings are superior in conveying the precise information.

Additionally, some people are tempted to use what are termed decorative visuals, such as clip art, in an attempt to seduce students into taking an interest in the topic at hand. This, too, is counterproductive. It diverts attention away from the lesson’s aims and, as a consequence, confuses and overloads. 

HOW2s are simple line drawings with all extraneous details cut out. Viewers don’t have to work hard to know where to look and what to notice. 

Well-designed visuals help the viewer construct new memories in their long-term storage, supporting a deeper understanding of the concepts and procedures involved. By locating all the elements on one page — viewed in one go — visuals present a coherent image that is more easily assimilated and stored away for future reference.

This is particularly relevant for educators. It’s one thing being inspired by a guru on a training day, and quite another to remember accurately the technique involved the following day in your classroom. 

No such problems occur with HOW2s. Unified, coherent step-by-step visuals offer easy-to-assimilate packaged models. When teachers discuss teaching techniques, the visual reference to a HOW2 will ensure they really are talking, precisely, about the same process. 

The simpler the visual model, the easier it is to retain it in memory for transfer into classrooms. By focusing solely on those aspects directly related to the teaching technique in question, the visual model helps the viewer identify key components necessary for deeper understanding.

HOW2s not only offer this level of simplicity and relevance but also stimulate a visceral viewing of the technique. By visceral I mean stimulating the imagination to feel as if one were there, in the diagram, so to speak, acting out the steps of the technique. Such an imagining of the future stimulates physical responses that are re-ignited again when the faculty is actually applying the HOW2 into their teaching.