Chemistry gives us two concepts for how to combine solids and liquids. A solution is when the particles of solid are dissolved by the liquid. A suspension is when the particles “float” in the liquid. Salt and sugar will dissolve in water, and once mixed, the combination is stable. The salt or sugar will not separate. It’s possible to mix sand and water to form a suspension, but over time, the sand will settle out unless more agitation is applied.
As we consider the combination of tools, content, and students, I think these mental models provide a metaphor to help us understand things like “text books” in a new light. A text combines words and pictures in a way that, ideally, creates a entity that’s different from words or pictures alone. Adding graphics to words creates a new thing — a kind of cognitive solution. Whether the solution is salty or sweet really depends on the precise nature of the words and pictures, but the point is that the text can’t be subdivided again without changing the nature of the product.
Classes are more like suspensions. We can add or subtract, modify and append, but the key to keeping the nature of the class consistent is the need to periodically apply agitation so that the components don’t settle out. I can add a text, subtract a chat, bring in outside speakers, and make almost any kind of change we could think of, and as long as I keep applying energy, the suspension will maintain integrity.
As you consider your tools and your class designs, remember that you need to know how the various tools work individually as a precursor to how they work together. Once you start combining them, the critical skill is knowing how they work together and what proportions meet your goals.