title: Revised Olweus Bully/Victim Questionnaire: evaluation in visually impaired.
abstract: OBJECTIVE
  To explore the psychometric properties of the revised Olweus Bully/Victim Questionnaire (OBVQ) in children with visual impairment (VI) using Rasch analysis.
  
  
  METHODS
  One hundred fifty Indian children with VI between 8 and 16 years (mean age, 11.6 years; 69% male; mean acuity in the better eye of 0.80 logMAR [Snellen, 20/126]) were administered the revised OBVQ. The 40-item revised OBVQ was developed to assess victimization (i.e., being bullied) and bullying (bullying others) in normally sighted schoolchildren. Only 16 items are used for Rasch analysis and are divided into two parts: I (victimization, eight items) and II (bullying others, eight items). Separate Rasch analysis was conducted for both parts, and the psychometric properties investigated included behavior of rating scale, extent to which the items measured a single construct (unidimensionality by fit statistics and principal component analysis [PCA] of residuals); ability to discriminate among participants' victimization and bullying behaviors (measurement precision as assessed by person separation reliability [PSR] minimum recommended value, 0.80); and targeting of items to participants' victimization and bullying.
  
  
  RESULTS
  Response categories were misused for both parts I and II, which required repair before further analysis. Measurement precision was inadequate for both parts (PSR, 0.64 for part I and 0.19 for part II), indicating poor discriminatory ability. All items fit the Rasch model well in part I, indicating unidimensionality that was further confirmed using PCA of residuals. However, an item misfit in part II that required deletion following which the remaining items fit and PCA of residuals also supported unidimensionality. Targeting was -0.58 logits for part I, indicating that the items were matched well with the participants' victimization. By comparison, targeting was suboptimal for part II (-1.97 logits).
  
  
  CONCLUSIONS
  In its current state, the revised OBVQ is not a valid psychometric instrument to assess victimization and bullying among children with VI.
authors.affiliation: Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, Andhra Pradesh, India. vijayagothwal@gmail.com
authors.forename: Vijaya K
authors.initials: VK
authors.lastname: Gothwal
authors.forename: Rebecca
authors.initials: R
authors.lastname: Sumalini
authors.forename: Shaik Mohammad
authors.initials: SM
authors.lastname: Irfan
authors.forename: Avula
authors.initials: A
authors.lastname: Giridhar
authors.forename: Seelam
authors.initials: S
authors.lastname: Bharani
mesh_terms: D000293:Adolescent; D044466:Asian People; D058445:Bullying / Q000523:psychology*; D002648:Child; D019548:Crime Victims / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D025341:Principal Component Analysis; D011594:Psychometrics / Q000295:instrumentation; D011788:Quality of Life; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D015354:Vision, Low / Q000523:psychology*; D014792:Visual Acuity; D019987:Persons with Visual Disabilities / Q000523:psychology*