title: Temporal Stability of the Dutch Version of the Wechsler Memory Scale-Fourth Edition (WMS-IV-NL).
abstract: OBJECTIVE
  The Wechsler Memory Scale-Fourth Edition (WMS-IV) is one of the most widely used memory batteries. We examined the test-retest reliability, practice effects, and standardized regression-based (SRB) change norms for the Dutch version of the WMS-IV (WMS-IV-NL) after both short and long retest intervals.
  
  
  METHODS
  The WMS-IV-NL was administered twice after either a short (M = 8.48 weeks, SD = 3.40 weeks, range = 3-16) or a long (M = 17.87 months, SD = 3.48, range = 12-24) retest interval in a sample of 234 healthy participants (M = 59.55 years, range = 16-90; 118 completed the Adult Battery; and 116 completed the Older Adult Battery).
  
  
  RESULTS
  The test-retest reliability estimates varied across indexes. They were adequate to good after a short retest interval (ranging from .74 to .86), with the exception of the Visual Working Memory Index (r = .59), yet generally lower after a long retest interval (ranging from .56 to .77). Practice effects were only observed after a short retest interval (overall group mean gains up to 11 points), whereas no significant change in performance was found after a long retest interval. Furthermore, practice effect-adjusted SRB change norms were calculated for all WMS-IV-NL index scores.
  
  
  CONCLUSIONS
  Overall, this study shows that the test-retest reliability of the WMS-IV-NL varied across indexes. Practice effects were observed after a short retest interval, but no evidence was found for practice effects after a long retest interval from one to two years. Finally, the SRB change norms were provided for the WMS-IV-NL.
authors.affiliation: a Academic Centre for Epileptology, Kempenhaeghe , Heeze , the Netherlands.|b Donders Institute for Brain, Cognition and Behaviour , Radboud University , Nijmegen , the Netherlands.
authors.forename: Zita
authors.initials: Z
authors.lastname: Bouman
authors.affiliation: a Academic Centre for Epileptology, Kempenhaeghe , Heeze , the Netherlands.|b Donders Institute for Brain, Cognition and Behaviour , Radboud University , Nijmegen , the Netherlands.
authors.forename: Marc P H
authors.initials: MP
authors.lastname: Hendriks
authors.affiliation: a Academic Centre for Epileptology, Kempenhaeghe , Heeze , the Netherlands.|c Department of Neurology and School for Mental Health and Neuroscience , Maastricht University Medical Centre , Maastricht , the Netherlands.|d Department of Neurology , University Hospital Gent , Gent , Belgium.|e Faculty of Electrical Engineering, Signal Processing System Group , Technical University Eindhoven , Eindhoven , the Netherlands.
authors.forename: Albert P
authors.initials: AP
authors.lastname: Aldenkamp
authors.affiliation: b Donders Institute for Brain, Cognition and Behaviour , Radboud University , Nijmegen , the Netherlands.|f Department of Medical Psychology , Radboud University Medical Center , Nijmegen , the Netherlands.
authors.forename: Roy P C
authors.initials: RP
authors.lastname: Kessels
mesh_terms: D000328:Adult; D002658:Developmental Disabilities / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D009426:Netherlands; D009483:Neuropsychological Tests / Q000592:standards; D014888:Wechsler Scales
keywords: Episodic memory; Neuropsychological assessment; Practice effects; Reliable change.; Test battery; Test–retest reliability