Accessibility in the sense used here is primarily about language and contexts, rather than content. A prompt that addresses unfamiliar content knowledge may still be appropriate so long as the language and context are clear. For instance, “About how many plates does Earth have?” may address content with which students have no experience. Even with an “I don’t know” answer, this prompt may be useful. The response quickly informs the teacher or researcher that plate tectonics is likely unfamiliar territory. And because “plates” is probably the only term in the prompt that students may have trouble defining, this knowledge deficiency likely the one that leads to the “I don’t know” response.
Consider the following prompts with respect to language:
”Do plants respire in the dark? Why or why not?“ versus ”Do plants need energy when it’s dark? Why or why not?“
The first prompt could present a barrier to eliciting student ideas. Students may not yet know the word respire and thus this prompt might fail to elicit a response that reveals the student’s thinking. Alternatively, students might interpret it as a reference to the breathing of air, and resulting responses would likely steer the discussion away from the targeted concept. In either case, the wording of this prompt may keep it from eliciting students’ ideas about whether plants need energy in the dark. The language in the second prompt is more accessible to students.