Get Item True Mastery Probability — calc_item_true_positive

Calculates the probability a student answers this item correctly GIVEN they possess all required skills (True Master).

Usage

calc_item_true_positive_prob(results, item)

Arguments

results: The full pgdcm results list object.
item: A string item ID (e.g., "1") or integer index.

Value

A list containing the target item, posterior mean mastery probability, and 95

Semantic Interpretation

* **High Value (> 0.8)**: Excellent item alignment. True Masters can reliably demonstrate their proficiency cleanly on this item. * **Low Value (< 0.5)**: A flawed or "slipping" item. Even true Masters often fail this item, suggesting the question is confusingly worded, computationally exhausting, or requires an unmodeled secondary skill (like advanced reading comprehension).