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Comparing a single case with a control sample: correction and further comment.

Michael C Corballis¹

¹Department of Psychology, University of Auckland, Auckland 1142, New Zealand. m.corballis@auckland.ac.nz

Neuropsychologia

|April 23, 2009

Summary

This summary is machine-generated.

The t-test for comparing a single case to a control sample is incorrect. Analysis of variance is recommended for factorial designs, but not for neuropsychological dissociation studies.

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Area of Science:

Neuropsychology
Statistical Methods

Background:

A previously suggested t-test for comparing a single case to a control sample has been identified as incorrect.
The corrected formula has ambiguous interpretations regarding single-case belongingness to a population or mean comparison.

Discussion:

The t-test is inappropriate for determining if a single case belongs to a control sample's population.
The corrected t-test can be interpreted as comparing the single case's mean to the control sample's population mean.

Key Insights:

The t-test is not suitable for single-case analysis against control groups in all contexts.
Analysis of variance (ANOVA) is a recommended alternative for factorial experiments involving single cases and control samples under varied conditions.

Outlook:

Further statistical method development is needed for single-case research.
Clarification on appropriate statistical tests for neuropsychological dissociation research is essential.