These programs for PCs accompany the paper: Crawford, J. R., Garthwaite, P. H., & Wood, L.T. (2010). Inferential methods for comparing two single cases. Cognitive Neuropsychology, 27, 377-400.
The programs allow researchers to compare the scores of two single cases. Unlike existing methods of comparing two cases it refers the scores of the two cases to a control sample. (See the paper for a discussion of the issues arising when control data are not used). All of the methods provide a significance test (one and two-tailed), point and interval estimates of the effect size for the difference, and point and interval estimates of the percentage of pairs of controls that will exhibit a larger difference than that observed for the cases (i.e., these latter statistics quantify the abnormality of the difference). There is the option of allowing for the effects of covariates when comparing the cases (see below). The control data can be in the form of summary statistics or raw data.
C_CTC.exe implements a classical test for the difference between the scores of two single cases. Click here to download the executable file; or here to download a zip file containing all five programs.
B_CTC.exe implements a Bayesian Monte Carlo method of examining the difference between the scores of two single cases. The Bayesian and classical methods converge (i.e., the results are identical save for trivial differences arising from Monte Carlo variation); this is reassuring whether one is classical, Bayesian, or eclectic in orientation. Click here to download the program as an executable file; or here to download a zip file containing all five programs.
CTC_Cov.exe compares the scores of two cases on a task of interest but, unlike the first two programs, allows for the effect of a covariate (e.g., a researcher may wish to compare the scores of two single cases allowing for the effect of years of education). Click here to download the executable file; or here to download a zip file containing all five programs.
CTC_Vec_Cov.exe extends CTC_Cov.exe to allow for multiple covariates (i.e., a vector of covariates). It takes summary data for the control sample as input data (i.e., the control means, SDs, and correlation matrix). Click here to download the executable; or here to download a zip file containing all five programs.
CTC_Vec_Cov_Raw.exe also allows a researcher to compare two cases allowing for multiple covariates but takes raw scores for the control sample as input data . Click here to download the executable file; or here to download a zip file containing all five programs.
The author of this software (John R Crawford) and the University of Aberdeen make no representations about the suitability of the software or about any content or information made accessible by the software, for any purpose.
The software is provided 'as is' without express or implied warranties, including warranties of merchantability and fitness for a particular purpose or noninfringement.
The software is provided gratuitously and, accordingly, the author shall not be liable under any theory or any damages suffered by you or any user of the software.
If there are any problems please e-mail me at j.crawford@abdn.ac.uk. Further contact details are available in the footer of this page.
