On the communication of information by displays of standard errors and confidence intervals

A survey of practices regarding the presentation of information about reliability of means in psychological research publications over the last century reveals some advance in quality of communication, greater for tabular presentations than for graphic presentations, but also substantial room for improvement. In this article, problems of interpretation and communication associated with presentations of standard errors and confidence intervals in research reports are examined from both statistical and psychological perspectives. Four general principles of effective communication are proposed and illustrated in application to presentations of data from common psychological research designs, with special attention to problems arising in connection with repeated measures.