Test Statistics Report

The Test Statistics report displays detailed information about tests and items.

Access the Report

1. From the main navigation menu, choose Reports, then Test Statistics.
2. Choose a test.

• Tests are only available if they:
  • Honor the filters set for school, teacher, course, or class.
  • Are released.
  • Have generated and loaded student data in the overnight data build.
• Results will not display for tests scanned or submitted the same day or for students to whom you do not have access.
• The Analyzed Items count excludes:
  • Students who answered all items correctly or all items incorrectly.
  • Items that were answered correctly by all students or incorrectly by all students.
  • All dichotomous items.

Summary

The Summary displays student performance, test statistics, and summary charts.

Student Performance Panel

1. The Student Performance panel provides detailed student performance data.
   1. Hover over a Student Achievement band to display its label and the total number of students who scored in that band.

   2. From Finished Students, click View List to display students and their student ability. This value scales student ability against the question difficulty.

      

      The list only displays students who are scheduled to you. The total number of displayed students may be less than the total of students who finished the assignment.

2. Optionally, click Student Item Analysis to navigate to the Student Item Analysis report for the selected assessment.

Test Statistics Panel

The Test Statistics panel displays the Classical Statistics and 2PL Statistics for tests.

Value	Description
Mean Item Difficulty	The average difficulty level of all of the assessment's items.
Classical Statistics	The total number of items included in this data, the min P, and the max P.
2PL Statistics	Total number of items included in the data, the mean item difficulty, the min b, the max b, the mean item discrimination, the min a, and the max a 2PL includes only pure dichotomous items which include Answer Key Only (AKO) choice item types and tests from item banks with one possible correct answer.
Items Aligned to Standards	Click Items Aligned to Standards to display a list of the standards and the question to which they are aligned.

Summary Charts Panel

The Summary Charts panel includes:

• Distribution of Proportion Correct by Student
• Distribution of Student Ability (Theta)
• Item-Person Map
• Distribution of Question Discrimination (a)*
• Distribution of Question Difficulty (b)*
• Difficulty (b) vs. Discrimination (a)*
• Test Response Function
• Test Information Function
• Conditional SEM Function

*These charts are not available for tests containing non-dichotomous items.

If an item's difficulty value is above or below the expected values of -4 < b < +4, the item is not included in the Difficulty (b) vs. Discrimination (a) and Distribution of Question Difficulty (b) charts.

Items Tab

1. Click the Items tab to analyze individual items in detail.
2. Choose from the following options:
   • Select to group items by type, complexity, or standard.
   • Click Create Graph to make selections, then create and export a graph.
   • Click Manage Columns to display or hide columns.
   • Click Export to export as a Microsoft Excel file.
3. Optionally, you can apply a column filter.
   1. Click a column header.
   2. Make the necessary selections, then click Apply.

Section	Description
Group By	Choose to group the items by Type, Complexity, or Standard.
Create Graph	Click Create Graph. Select specific criteria to create a custom graph. Click Next.
Manage Columns	Click Manage Columns. Select or clear column selections. Click Apply.
Export	Click Export to download a Microsoft Excel file.
Item	This column displays the question number and Item ID. Click the Item ID to display the Item Creation page.
Type	The item type is indicated in this column. At this time, only the data for Choice and T/F interactions is analyzed. Click the graph icon to expand the row and display the Halydana Chart: This is only available for single-choice items with a single correct response.
P-Value	Identifies the P-Value for this item.
Alpha Without	Identifies the Alpha Without value for this item.
Discrimination (Classical)	Identifies the Discrimination value for this item.
Corrected Point Biserial	Identifies the Corrected Point Biserial for this item.
Discrimination (2PL)	Identifies the 2PL discrimination value for this item. 2PL includes only pure dichotomous Items which include Answer Key Only (AKO) choice item types and tests from item banks with one possible correct answer.
Difficulty (2PL)	Identifies the 2PL difficulty value for this item. 2PL includes only pure dichotomous Items which include Answer Key Only (AKO) choice item types and tests from item banks with one possible correct answer.
Choice Distribution	All possible answer choices are displayed with the percentage of students who selected each response. This does not apply to items that have more than one correct response.
Complexity	Identifies the Complexity level assigned to the item in the item attributes.