Communication deviance (CD) refers to confusing and fragmented communication that prevents family members from attaining a shared focus of attention and meaning. Levels of communication deviance based on individual parental projective test protocols--Thematic Apperception Test (TAT) and Rorschach--have repeatedly been found to be higher in parents of schizophrenic offspring than in parents of normal or nonpsychotic offspring. CD has also been measured in family transactions in which parents and their offspring interact with one another around a projective test stimulus, the Consensus Rorschach. There have been relatively few attempts to measure specific CD codes in familial interaction that is not initiated around an ambiguous visual stimulus. The present article examines the reliability and construct validity of an interactional measure (ICD) obtained from family transactions in which parents and patients are working toward the solution of a salient family problem. ICD from this family problem-solving task was compared to more traditional measures of CD from parental TAT protocols in a sample of 59 parents of 37 recent-onset schizophrenic patients. Results indicated that CD could be reliably measured in an interactive setting not initiated around a projective test stimulus, and provided evidence for the construct validity of ICD.