reliability

reliability

1. classical theory of measurement

   • consistency
   • inconsistency

2. test - retest

3. alternate forms

4. internal consistency

   • split half
   • spearman-brown formula
   • Coefficient alpha
   • The Kuder-Richardson Estimate of Reliability
   • Interscorer Reliability

5. Theories

   • Item Response Theory / Latent Trait Theory
     • Foundational elements
       • Item response functions (IRF) / Item Characteristic Curve (ICC)
       • Information functions
       • Assumption of invariance
     • The standard error of measurement becomes substantially larger at both extremes of ability
     • Shorter tests can be more reliable than longer tests
     • Better suited for computerized adaptive testing
   • Classical Test Theory
     • The standard error of measurement is assumed to be a constant that applies to all examinee scores regardless of the ability level of a participant
     • Longer tests are more reliable than shorter tests