title: A brief Dutch language Impact Message Inventory-Circumplex (IMI-C Short) using non-parametric item response theory.
abstract: OBJECTIVE
  Non-Parametric IRT methods were applied to 127 clinicians' ratings of their patients using the Dutch Impact Message Inventory-Circumplex (IMI-C) to develop the IMI-C Short.
  
  
  METHODS
  Four items from each octant subscale of the IMI-C were selected to maximally differentiate individuals along the continuum of impact messages.
  
  
  RESULTS
  Using larger samples (patients: N = 700, 812; raters: N = 42, 85, respectively), IRT-based reliability was generally comparable between the brief and parent subscales. Classical Test Theory-based reliability was adequate for the brief subscales and they converged with their parent subscales. Since the IMI-C is purported to represent the circular arrangement of impact messages, the fits of the parent and abbreviated scales were assessed and found to be good and not differ significantly.
  
  
  CONCLUSIONS
  The new IMI-C Short offers advantages over the full-length IMI-C.
authors.affiliation: a Counseling, School, and Educational Psychology , University at Buffalo-SUNY , Buffalo , NY , USA.
authors.forename: Sandro M
authors.initials: SM
authors.lastname: Sodano
authors.forename: Terence J G
authors.initials: TJ
authors.lastname: Tracey
authors.forename: Anton
authors.initials: A
authors.lastname: Hafkenscheid
mesh_terms: D000328:Adult; D001530:Belgium; D003142:Communication; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000523:psychology / Q000628:therapy*; D008875:Middle Aged; D009426:Netherlands; D011369:Professional-Patient Relations; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D011582:Psychological Theory; D011594:Psychometrics / Q000295:instrumentation*
keywords: IMI-CS; Impact Message Inventory–Circumplex; Impact Message Inventory–Circumplex Short; interpersonal circle; non-parametric item response theory