Tina Rooks's List: item analysis

• Performing Item Analysis

• Item Analysis: An Internet Application

• Type of Reliability	How to Measure
  Stability or Test-Retest	Give the same assessment twice, separated by days, weeks, or months. Reliability is stated as the correlation between scores at Time 1 and Time 2.
  Alternate Form	Create two forms of the same test (vary the items slightly). Reliability is stated as correlation between scores of Test 1 and Test 2.
  Internal Consistency (Alpha, a)	Compare one half of the test to the other half. Or, use methods such as Kuder-Richardson Formula 20 (KR20) or Cronbach's Alpha.

• C. Item Analysis

• Test Item Analysis Using Microsoft Excel Spreadsheet Program

• Eight Simple Steps to Item Analysis

• Introduction to Item Analysis
• Item Analysis Response Patterns
• The INDEX OF DISCRIMINATION
• INDEX OF DIFFICULTY

• Item Analysis Guidelines

  Item analysis is a completely futile process unless the results help instructors improve their classroom practices and item writers improve their tests. Let us suggest a number of points of departure in the application of item analysis data.

  1. Item analysis gives necessary but not sufficient information concerning the appropriateness of an item as a measure of intended outcomes of instruction. An item may perform beautifully with respect to item analysis statistics and yet be quite irrelevant to the instruction whose results it was intended to measure. A most common error is to teach for behavioral objectives such as analysis of data or situations, ability to discover trends, ability to infer meaning, etc., and then to construct an objective test measuring mainly recognition of facts. Clearly, the objectives of instruction must be kept in mind when selecting test items.
  2. An item must be of appropriate difficulty for the students to whom it is administered. If possible, items should have indices of difficulty no less than 20 and no greater than 80. lt is desirable to have most items in the 30 to 50 range of difficulty. Very hard or very easy items contribute little to the discriminating power of a test.
  3. An item should discriminate between upper and lower groups. These groups are usually based on total test score but they could be based on some other criterion such as grade-point average, scores on other tests, etc. Sometimes an item will discriminate negatively, that is, a larger proportion of the lower group than of the upper group selected the correct option. This often means that the students in the upper group were misled by an ambiguity that the students in the lower group, and the item writer, failed to discover. Such an item should be revised or discarded.
  4. All of the incorrect options, or distracters, should actually be distracting. Preferably, each distracter should be selected by a greater proportion of the lower group than of the upper group. If, in a five-option multiple-choice item, only one distracter is effective, the item is, for all practical purposes, a two-option item. Existence of five options does not automatically guarantee that the item will operate as a five-choice item.
• Item Analysis Guidelines
• Interpreting the Index of Discrimination document contains a more detailed discussion of the index of discrimination.

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• WHAT MAKES AN ITEM PSYCHOMETRICALLY GOOD?
• A few basic rules for item development follow:

• Interpreting Item Analysis

• Steps in a review of an item analysis report