Grade Approach to the Analysis of Questionnaires and Clinical Scales Data

Grade approach has been applied to visualize and reinvestigate a dataset from diagnostic questionnaires and scales used in psychological and psychiatric clinical practice. Grade exploration reveals important hidden variables strongly influencing other variables and splits questionnaire data into more regular monotone dependent blocks. Two sets of homogeneous and ordered clusters of patients, formed on the basis of first line variables and described also by second line variables, expose links between neurosis symptoms and Internal or External Locus of Control as well as prove useful for specifying and verifying diagnoses. All analyses were performed using the GradeStat program.