The RTD Theory of the Item explains the fundamental nature of CDPs’ (content development professionals) work in crafting and refining items. It connects content, test takers, evidence and the role/work of CDPs in making those connections work properly. You can download the chapter linked on the left to read a fuller explanation than we provide below.
TotI (Theory of the Item) explains that CDPs begin with some cognition (e.g., a standard or a KSA) that the item will target. They then must imagine a cognitive task that makes use of that cognition to produce some result. That task must appropriately depend on the targeted cognition — meaning that it is the key step, the hardest element, the move that test takers are most likely to stumble over. This in itself is a difficult task for the CDPs.
Then, CDPs must create an item that prompts test takers to engage in that cognitive task. In some cases, it is self-evident how to do that once the cognitive task is envisioned. In other cases, communicating clearly and succinctly what is expected of test takers is more much difficult.
TotI rests on ECD’s (evidence centered design) principle that tests — and items — should produce observable evidence of test taker proficiency. Thus, TotI points out that the cognitive task should lead to some test taker work product that constitutes high quality evidence of that proficiency. That is, the item should prompt a cognitive task that generates high quality evidence of the targeted cognition.
What the RTD TotI adds to our understanding of items and the work of developing them is the degree to which CDPs must account for test takers and the different possible responses that they have to an item. Test takers may engage in the intended task foreseen by the CDPs, either successfully or unsuccessfully. They may engage in an alternate task, which conceivably could produce misleading evidence. They may engage in some other cognition that prevents — or at least delays — them from producing any evidence at all. This other cognition may even disrupt their thinking enough so that the work product they produce is as much a product of that disruption as of the intended task, preventing it from being meaningful evidence of proficiency (or lack thereof) with targeted cognition.
However, TotI — and, frankly, all of RTD — recognizes that test takers cannot be taken for granted and that they vary enormously. Each test taker comes in with their own identities, experiences and understandings. They even come in in different states (e.g., how rested they are, their mood, how hungry they are), such that even a single test taker can vary. The variability across test taking population makes the job of envisioning a cognitive task that will produce high quality evidence and crafting an item that prompts that cognitive task for the range of typical test takers work that is incredibly complex, intellectual, empathetic and demanding
The RTD Theory of Item illustrates how the item is at the center of all of this, connecting the targeted cognition, CDPs, test takers, work product and evidence.