Item Analysis

1
Item Analysis

• Differential Item Functioning (DIF) what is
  test bias?
• Example item functioning on the Stanford-Binet
• Item Response Theory (Latent Trait Analysis)
  links observed (manifest) variables that are
  actually measured to unobserved (latent)
  construct of interest educational attainment,
  disease severity, program effectiveness, etc.
• What is the latent trait on the GRE?

2
What IRT can do

• 1. precisely measure the difficulty or easiness
  of each item
• 2. determine the association of each item with
  the construct being measured
• 3. determine which items are biased
• 4. design a test with the fewest items necessary
  to measure the construct create an adaptive
  test

3
Test Administration

• Ethical Codes
• Should someone know their IQ score?
• Should anyone else?
• least stigmatizing label changing fashions in
  terminology
• Informed Consent
• Origin of ethical codes Nuremberg Trials
  Tuskegee experiment
• Tri-councils Ethical conduct for research
  involving humans
• A world without research?

4
Following Test Directions

• Why are test directions arbitrary and inflexible?
• Consequences of flexibility
• Is flexibility ever justified?
• What is the overall tone of test
  administration? What cultural assumptions are
  made? Are standardized tests culturally loaded?
• Can these factors make a difference?
• Ex Head Start study

5
How to create a bogus test

• 1. use inter-related items
• 2. use specific determiners (words such as all,
  always, often, sometimes, and usually, which
  suggest that the statement is true)
• 3. have more true than false items (70 of
  selections are true)
• 4. limit variability of scores take advantage
  of ceiling and floor effects
• 5. use obvious distractors

6
Testing and Individual Differences

• Most tests are designed for the middle-range of
  ability
• Out of level testing for exceptional samples