A new scale based on Rational Emotive Behavior Therapy and Self-Determination Theory: Devolepment of Rational Emotive Self Determination Scale (RESD)

In this study, Rational Emotive Behavioral Theory (REBT) and Self-determination Theory (SDT) brought together in order to develop a new scale operationalized as Rational Emotive Self Determination Scale (RESD). Purpose of research is not only to develop a scale but also to lead a new psychotherapeutic approach which would be an integration of REBT and SDT in future. The scale's aim is that among adolecsents, measuring irrational beliefs in the light of autonomy, competence and relatedness as basic psychological needs which underlined in SDT. The psychometric properties of 51 items of RESD was tested. The study conducted on clinical (N=220) and non-clinical (N=383) sample. Four studies were conducted to confirm the factor structure of the RESD, reliability of the scale and to assess its construct validity. In the study, in terms of the validity and reliability analyzes confirmed theoretical expectations and have yielded positive results. Results of exploratory and confirmatory factor analyses demonstrated that this scale yielded three factors. As reported in the appendix, both non-clinical and clinical sample of the resulting structures on the data item-level exploratory factor analysis, especially in the clinical sample data sets very clearly revealed the structure of the three factor structure. Reliability analyses showed internal consistency coefficient ranging from .76 to .88 among subscales. Test–retest reliability was conducted to examine the reliability of subscales showed that reliability coefficents are .88 for irrational beliefs of autonomy needs, .77 for irrational beliefs of relatedness needs and .91 for irrational beliefs of competence needs, which can be concluded the test-retest reliability of RESD was high. Test- retest analysis has provided sufficient evidence that RESD can make stable measurements. In order to confim its concurrent validity, RESD was tested with, first, Reynolds Adolescent Adjustment Screening Inventory (RAASI), Profile of Affective Distress (PAD), Basic Psychological Needs Scale (BPNS) which addresses need satisfaction of competence, autonomy, and relatedness from parents. The results showed that correlation between RESD and these three scales is ranging from medium to high. According to these promising results, the scale may suggest a different approach to psychotherapeutic field in the means of integrating both REBT and SDT theoretical frame works.