Referring to Technical Constraints

Once items have been added to the form following the instructions in Adding and Removing Items, you will be able to determine whether technical constraints are met.

• The first table displays the target, tolerance, and current values. A theta constraint is too complex to be represented by a single current value, so a green check mark or red X in the Current column indicates whether the constraint is met. The table rows are color-coded red or yellow if items on the form have values too low or too high to meet the constraints. To search all columns in the table, type in the Search field above it.

• At the top of the workspace, to the right of the form name, the “Technical Constraints” flag has a green check mark or red X to indicate whether or not all the constraints are met.

Sometimes a constraint cannot be applied because some items lack certain attributes; for example, a difficulty constraint cannot be applied if one of the items lacks the difficulty attribute. In such a case, a message appears below the constraint table explaining this and allowing you to open a window containing more details.

Below the constraint table are multiple graphs and in some cases more tables. You can hide a graph by clearing the Show / Hide Graph checkbox above it, or show it by marking the checkbox. Note that if there are no reference form items, the difference (diff) graphs are hidden entirely. Each graph shows performance level cutoffs. To view the scale score associated with each cutoff, select Show Scale Scores at the top right corner of the first graph.

The graphs and the other tables are as follows:

• Standard Error at Theta (SE / SEM) (graph): Standard error for a range of theta values. The gray line represents the reference form and the colored line represents the current form.

• Standard Error Difference at Theta (SE / SEM) (graph): Difference between standard error at theta on the current form and on the reference form.

• Expected percent correct at Theta (TCC) (graph): Expected percent correct for a range of theta values (this is the Test Characteristic Curve (TCC) divided by the total number of raw score points on the test). The gray line represents the reference form and the colored line represents the current form.

• TCC Difference (graph): The difference between the normalized Test Characteristic Curves of the reference form and the current form.

• Information at Theta (graph): The sum of the information on each item in the current form. The gray line represents the reference form and the colored line represents the current form.

• Information Diff at Theta (graph): The sum of the information on each item in the current form minus the same sum for the reference form.

• Scale Score & Conversion Table: If this table is not displayed by default, select Show Conversion Table to display it. A comparison of the reference form to the current form based on scale scores and performance levels. It can be very helpful if a client has special rules about where a form’s raw score cuts fall and how different they are from the reference form.

  Note that when a proficiency level constraint is present and there is no reference form, the conversion table displays the reference form numbers as infinite, but the constraint is regarded as valid.

  To search all columns in the table, type in the Search field above it.

• Summary Table: This customizable table provides additional information comparing the current form to the reference form based on specified criteria. To display this table, select a table name from the dropdown list.

  Users with permissions to create technical constraints can also configure summary tables for the bank. If no table exists in the dropdown list, or if you wish to create a new one or edit an existing one, click Configure and follow these steps in the pop-up that appears:

  1. Either select an existing table from the dropdown list at the top right, or click Create New Table. If creating a new table, enter a name in the Name field.

  2. To add a blank row, click Add Row.

  3. Edit any row by choosing a sequential row number, entering a meaningful criterion name (for example, “Total Items” or “Average Difficulty”), and selecting an attribute and function from the dropdown lists.

  4. Optional: To delete a row, click Delete beside it.

  5. Optional: To delete the selected table, click Delete Table. Click OK in the confirmation pop-up that appears.

  6. Repeat the steps above as necessary. Click Save. The pop-up closes and the new or edited table is available to view.