The House Tree Person Test was developed by John Buck was originally an outgrowth of the Good enough scale utilized to assess intellectual functioning. Buck felt artistic creativity represented a stream of personality characteristics that flowed onto graphic art. He believed that through drawings, subjects objectified unconscious difficulties by sketching the inner image of primary process. Since it was assumed that the content and quality of the House-Tree-Person was not attributable to the stimulus itself, he believed it had to be rooted in the individual's basic personality. Since the House-Tree-Person Test was an out cropping of an intelligence test, Buck developed a quantitative scoring system to appraise gross classification levels of intelligence along with at qualitative interpretive analysis to appraise global personality characteristics.

Scoring: The Post-Drawing Interrogation form consists of 60 questions varying from direct and concrete to indirect and abstract. Once the Post-Drawing Interrogation form has been administered and the interview has been completed, the examiner records items of detail, proportion, and perspective in the Scoring Folder. After completing the scoring tables, the examiner derives an IQ figure for the percentage of raw G, a net weighted score, a weighted "good" score, and a weighted "flaw" sore, which then comprise the items for the profile configuration.

Reliability and Validity: The manual for the House Tree Person Test contains no information on validity and reliability.