Assessment items can be grouped by learning objective(s) that are clustered and linked together in complexity. Assessments can use "thinkaloud"/"think about it" non-scored items to break long-term goals into short-term objectives. For example, an item about the utility and purpose of food webs can orient a student to later items assessing students' interpretation of a food web. Be clear about the goal of the science story or problem, e.g., Paul wants to find out if a heavy ball and a light ball roll downhill at the same speed.
A "thinkaloud" item that does not orient the learner to upcoming assessed concepts and instead distracts the learner, such as an item asking about learner preferences or experience with different ecosystems when the tested constructs are around interpreting a food web. Also, putting complex items first and then lead-up items after or including items that do not relate to the problem to be solved.
Consider how students with visual impairments or communication support needs can respond to a "thinkaloud" question.