title: Reliability and validity of the ''personal well-being index- cognitive disability'' on mentally retarded students.
abstract: OBJECTIVE
  Having a good quality of life has always been desirable for humans, and the concept of a good life and the ways of achieving it have become important over the years. Personal wellbeing is the mental component of quality of life. Thus, the current study was conducted to assess the reliability and validity of the ''Personal Well-Being Index- Cognitive Disability'' on mentally retarded students.
  
  
  METHODS
  200 mentally retarded students in north districts of Tehran (districts 1, 2 and 3) were selected by systematic random sampling. The collected data using Personal Well-Being Index- Cognitive Disability was analyzed by Cronbach's alpha coefficient for internal consistency and linear multivariate regression for construct validity.
  
  
  RESULTS
  Results confirmed the reliability and validity for the Personal Well-Being Index- Cognitive Disability in mentally retarded students of exceptional schools. Studying the internal consistency of seven items showed that all the items were correlated with the total score and their scores averages were similar to each other. This indicates that the test's questions have reliability with regard to evaluation of a common feature and results showed Personal Well-Being Index- Cognitive Disability had the most extensive coverage of construct validity.
  
  
  CONCLUSIONS
  Personal Well-Being Index- Cognitive Disability scale could be applied to measure personal wellbeing in mentally retarded students.
authors.affiliation: Associate Professor of Psychology Payam-e-Noor University, Tehran, Iran.
authors.forename: Alireza Agha
authors.initials: AA
authors.lastname: Yousefi
authors.forename: Kambiz
authors.initials: K
authors.lastname: Mozaffari
authors.forename: Nasim
authors.initials: N
authors.lastname: Sharif
authors.forename: Mohammad
authors.initials: M
authors.lastname: Sepasi
keywords: Cognitive Disability; Mentally retarded student; Personal Well-being; Reliability; Validity