Calculating the confidence interval of correlation coefficients using syntax in SPSS

Abstract

Introduction: The association between two variables is expressed analytically by calculating the statistic called the correlation coefficient. In order to make sound research decisions, good research practice requires reporting not only the p-value but the confidence interval. While SPSS is the most commonly used statistical software in the socio-educational field, it does not provide the calculation of the confidence interval for the correlation coefficients in its usual routines. Therefore, the main objective of this study was to use a practical case to calculate by SPSS syntax the confidence interval for the correlation coefficients, highlighting the importance of reporting a confidence interval and providing a model for writing the results of a correlation study in a scientific report. Method: Two SPSS syntax files are provided, one for small samples and one for large samples, as a useful tool to calculate the confidence interval of a correlation coefficient. Results and discussion: The use of syntax files provides the researcher familiar with SPSS with a quick and easy way to calculate the confidence interval for a correlation coefficient.