Element Interactivity

What it is

Some material can be learned one piece at a time. Other material cannot, because the pieces only make sense in relation to one another. Element interactivity is the name for that difference. In plain terms, it asks how many things a learner must keep in working memory together, and how tightly they depend on one another, before the task can be understood. This plain-terms gloss is ours; it is offered to make the idea usable, not as a definition taken from the paper.

Sweller's 2010 paper, Element Interactivity and Intrinsic, Extraneous, and Germane Cognitive Load, makes the idea central. He writes that element interactivity has long been the basic mechanism defining intrinsic load, the load that comes from the task itself. His new argument is that it also underlies extraneous load, the load imposed by how the instruction is designed. The distinction between the two then turns on one question: is the interactivity needed for the task, or did the design of the instruction produce it? The paper defines germane load in terms of intrinsic load, so it too is tied to element interactivity. The paper also analyses what these definitions imply for the various effects found in cognitive load research, including those described on the worked example, split-attention and expertise reversal pages.

The idea connects the theory to its starting point. Working memory is small, so tasks with many interacting elements are the ones likely to exceed it, and an instructional design that adds interacting elements the task does not require adds load for nothing.

In effect

The 2010 paper

The research case is Sweller's paper, which reworks the definitions of the three kinds of load around one mechanism. It is a theoretical analysis rather than a single experiment.

Days of the week and the terms of an equation

An illustration, not a result. Learning the days of the week in order involves elements that can be taken one after another. Understanding how the terms of an equation constrain one another involves holding several at once, since changing one changes what the others must be. The second task has higher element interactivity.

A pricing page with interlocking options

Another illustration from design. A pricing page with three plans, each differing on several features that bear on each other, asks a visitor to hold many related elements together to choose. The same information set out so that each decision can be made separately has lower interactivity. Whether the extra interactivity is needed or produced by the page is the question the 2010 framing puts.

What it does not say

It does not supply a number. No method of measuring element interactivity is described here.

It does not settle the vocabulary. Ton de Jong's 2010 review in Instructional Science sets out conceptual and methodological problems with cognitive load theory, and the categories of load remain a subject of argument.

It does not establish who first used the term. The 2010 paper describes it as long established in the theory, and its earlier history is not traced here.

No figures from the paper are given.

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