Article

We describe a standardised mean difference statistic (d) for single-case designs
that is equivalent to the usual d in between-groups experiments. We show how it
can be used to summarise treatment effects over cases within a study, to do power
analyses in planning new studies and grant proposals, and to meta-analyse effects
across studies of the same question. We discuss limitations of this d-statistic,
and possible remedies to them. Even so, this d-statistic is better founded
statistically than other effect size measures for single-case design, and unlike
many general linear model approaches such as multilevel modelling or generalised
additive models, it produces a standardised effect size that can be integrated
over studies with different outcome measures. SPSS macros for both effect size
computation and power analysis are available.

Langue : ANGLAIS