Classical Test Theory¶
Research Method · All research methods
Evidence · 4 claims (4 for) · 2 studies (2 associational),q3· 0 of 2 report an effect size · 4 claims rest on one study
Description¶
CTT (True Score Theory) describes an observed score as composed of a true score and random error, estimating true scores from observed scores. The article lists limitations: "item parameters are dependent on the group to which a test is administered", no item-level evaluation of individuals, one standard error for all individuals, difficulty achieving high reliability with few items, and ordinal-scale data. Its advantages are few assumptions, simple computations, and usability with small samples.
Accounts¶
- Classical Test Theory (CTT) and its stated limitations: CTT (True Score Theory) describes an observed score as composed of a true score and random error, estimating true scores from observed scores. The article lists limitations: "item parameters are dependent on the group to which a test is administered", no item-level evaluation of individuals, one standard error for all individuals, difficulty achieving high reliability with few items, and ordinal-scale data. Its advantages are few assumptions, simple computations, and usability with small samples. (Ilhan et al. (2018))
Claims¶
- CTT and MFRM yield a positive, perfect correlation between item difficulty indices for open-ended items under a crossed design [+M]
- CTT and MFRM yield similar item difficulty results for open-ended questions regardless of crossed or nested design [+W]
- Items ranked from easiest to most difficult are identical under CTT and MFRM [+W]
- CTT-based quiz difficulty rankings are validated by IRT analysis with near-perfect rank correlation [+W]
Related Research Methods¶
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Key Sources¶
- Ilhan, M., & Guler, N. (2018). A Comparison of Difficulty Indices Calculated for Open-Ended Items According to Classical Test Theory and Many Facet Rasch Model. Eurasian Journal of Educational Research, 75. doi:10.14689/ejer.2018.75.6
Page metadata
| Field | Value |
|---|---|
type |
research-method |
id |
classical-test-theory |
title |
Classical Test Theory |
description |
CTT (True Score Theory) describes an observed score as composed of a true score and random error, estimating true scores from observed scores. |
status |
review |
moved_from |
theory/ctt-assumptions-and-limitations-ilhan-2018 |
generated |
by process:sweep-kinds on 2026-10-10 |
trust |
unverified — no one has confirmed this page's content |
sources |
1 — ilhan-2018 |
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