Sentence examples for explanations were coded from inspiring English sources

Explanations were coded for structural and functional content, arrows, specific examples, and multiple representations.

Visual and verbal explanations were coded for depicting or describing structural and functional components.

Explanations were coded for structural and functional information, arrows, specific examples, and multiple representations.

Explanations were coded for structural and functional content, essential features, invisible features, arrows, and multiple steps.

The explanations were coded for the number of discrete steps used to explain the process of using the bike pump.

Explanations were coded for the use of specific examples, such as NaCl, to illustrate ionic bonding and CO2 and O2 to illustrate covalent bonding.

Many visual explanations (67%) contained verbal components; the structural and functional information in explanations was coded as depictive or descriptive.

Explanations (see Fig. 2) were coded for structural and functional content, essential features, invisible features, arrows, and multiple steps.

For the visual explanations, three uses of arrows were coded and tallied: labeling a part or action, showing motion, or indicating sequence.

The key features from the paper, together with an explanation on how the meaning units were coded into each category are presented at Table  1.

A subset of the explanations (20%) was coded by the first author and another researcher using the same coding system as a guide.