An investigation of the construct validity of the Bannister-Fransella Grid Test of Schizophrenic Thought Disorder.

An attempt was made to demonstrate the construct validity of the Grid Test in a psychiatric population by showing that: (a) judgements of thought disorder based on the Grid Test were associated with judgements based on a clinical interview; (b) Grid Test scores were not associated with measures of other forms of psychopathology, intelligence, or memory. Results of a principal components factor analysis confirmed both hypothesis, supporting the validity of the Grid Test as a measure of thought disorder.