title: Revised Knox Preschool Play Scale: interrater agreement and construct validity.
abstract: OBJECTIVE
  Interrater agreement and construct validity of the Revised Knox Preschool Play Scale (RKPPS) were examined.
  
  
  METHODS
  Two separately trained raters evaluated 38 typically developing children, ages 36 to 72 months. For each child, the raters observed two 15-min free-play sessions.
  
  
  RESULTS
  For the overall play age, the scores of the two raters were within 8 months of each other 86.8% of the time; for the 4 dimension scores, they were within 12 months of each other 91.7% to 100% of the time; and for the 12 category scores, they were within one age level of each other 81.8% to 100% of the time. Construct validity results showed a general match between the children's chronological ages and their overall play age scores.
  
  
  CONCLUSIONS
  Findings suggest that two raters can score the RKPPS with some consistency and that scores on this measure progress developmentally, thus supporting its construct validity.
authors.affiliation: Division of Occupational Therapy, Department of Rehabilitation Medicine, University of Washington, Seattle, USA.
authors.forename: Milena
authors.initials: M
authors.lastname: Jankovich
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Mullen
authors.forename: Erin
authors.initials: E
authors.lastname: Rinear
authors.forename: Kari
authors.initials: K
authors.lastname: Tanta
authors.forename: Jean
authors.initials: J
authors.lastname: Deitz
mesh_terms: D002648:Child; D002665:Child Psychiatry; D002675:Child, Preschool; D003142:Communication; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D009788:Occupational Therapy; D010372:Pediatrics; D010552:Personality Assessment; D010988:Play and Playthings; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D012944:Social Support; D014861:Washington