Volume 7 · Reliability, validity, test construction

A finding is only ever as good as the measure it rests on.

Twelve days on measurement you can defend: classical test theory, every reliability coefficient and what it actually estimates, the four myths about alpha, validity as evidence rather than a category, item analysis by hand, item response theory, differential item functioning, norms, and building a scale from a construct definition to a cut-off.

12
days of 45–55 min
6
forms of the ICC
10
stages of scale building
4
myths about alpha
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The mistake this topic produces
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Do this now · 15 minutes
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Reference

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Checkpoint

Ten questions before you move on

Reliability, validity and test construction are the most heavily examined topics in psychology entrance papers, and the ones applied work gets wrong most often.

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Next: volume 8, Designs & domains

Twelve days on matching the analysis to the study: experimental and quasi-experimental design, validity threats, counterbalancing, single-case designs, longitudinal and time-series data, survey and missing data, reaction times, signal detection, and the statistics of neuroimaging and EEG.

Start day 89 →