title: A new approach to integrating data from multiple informants in psychiatric assessment and research: mixing and matching contexts and perspectives.
abstract: OBJECTIVE
  When there exists no single source of information (informant) to validly measure a characteristic, it is typically recommended that data from multiple informants be used. In psychiatric assessment and research, however, multiple informants often provide discordant data, which further confuse the measurement. Strategies such as arbitrarily choosing one informant or using the data from all informants separately generate further problems. This report proposes a theory to explain observed patterns of interinformant discordance and suggests a new approach to using data from multiple informants to measure characteristics of interest.
  
  
  METHODS
  Using the example of assessment of developmental psychopathology in children, the authors propose a model in which the choice of informants is based on conceptualizing the contexts and perspectives that influence expression of the characteristic of interest and then identifying informants who represent those contexts and perspectives in such a way as to have the weaknesses of one informant canceled by the strengths of another.
  
  
  RESULTS
  Applications of this approach to several datasets indicate that when these principles are followed, a more reliable and valid consensus measure is obtained, and failure to obtain a reliable, valid measure is indicative of some deviation from the principles.
  
  
  CONCLUSIONS
  In obtaining a consensus measure, the issue is not determining how many informants are needed but choosing the right set of informants.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Stanford University, 4012 Quarry Road, MC 5717, Stanford, CA 94305, USA. HCK@stanford.edu
authors.forename: Helena C
authors.initials: HC
authors.lastname: Kraemer
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Measelle
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Ablow
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Essex
authors.forename: W Thomas
authors.initials: WT
authors.lastname: Boyce
authors.forename: David J
authors.initials: DJ
authors.lastname: Kupfer
mesh_terms: D000328:Adult; D002648:Child; D003625:Data Collection / Q000379:methods*; D002658:Developmental Disabilities / Q000175:diagnosis / Q000523:psychology; D005260:Female; D006801:Humans; D007407:Interviews as Topic / Q000379:methods; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis* / Q000523:psychology; D008962:Models, Theoretical; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011594:Psychometrics / Q000379:methods*; D015203:Reproducibility of Results; D012107:Research Design