Figure 1.

Test information function (TIF) of revised the CCSS-NCQ domains. Each TIF is made up of the sum of item information function (IIF) and represents the total amount of information provided by the domains. The amount information provided by each item is determined by the size of the discrimination or slope (i.e., height of curve) and the spread of the category thresholds. $(\text{IIF}:I_i\left(\theta \right)=\sum _{x=0}^m{P}_{\mathit{\text{ix}}}{\left(\theta \right)}^2÷P_{\mathit{\text{ix}}}\left(\theta \right);\text{TIF}:I\left(\theta \right)=\sum _{i=t}{I}_i\left(\theta \right)$ (Embretson & Reise, 2000))