title: Group-item and directed scanning: examining preschoolers' accuracy and efficiency in two augmentative communication symbol selection methods.
abstract: OBJECTIVE
  The current investigation compared directed scanning and group-item scanning among typically developing 4-year-old children. Of specific interest were their accuracy, selection speed, and efficiency of cursor movement in selecting colored line drawn symbols representing object vocabulary.
  
  
  METHODS
  Twelve 4-year-olds made selections in both directed and group-item scanning conditions using a 36-symbol array that required matching line drawn symbols to pictures.
  
  
  RESULTS
  The majority of participants took more time in the directed scanning condition. Though not statistically significant, participants tended to be more accurate in their use of directed scanning. The cursor movements required (as a proportion of optimal cursor movements) were similar for both scanning selection techniques.
  
  
  CONCLUSIONS
  Among typically developing 4-year-olds, there appears to be a trade-off between speed and accuracy in symbol selection when using directed or group-item scanning. Better accuracy with directed scanning appears to come at the cost of a slower response time. Whereas group-item scanning may be faster, it results in a decreased number of accurate responses. Applications for clinical practice and implications for future research are discussed.
authors.affiliation: University of Minnesota, Minneapolis, USA. whit0950@umn.edu
authors.forename: Aubrey Randall
authors.initials: AR
authors.lastname: White
authors.forename: Edward
authors.initials: E
authors.lastname: Carney
authors.forename: Joe
authors.initials: J
authors.lastname: Reichle
mesh_terms: D002657:Child Development; D002675:Child, Preschool; D016287:Computer Peripherals; D003200:Computer User Training / Q000379:methods*; D003194:Computer-Assisted Instruction / Q000379:methods*; D006801:Humans; D010775:Photic Stimulation / Q000379:methods*; D013561:Symbolism; D013663:Teaching / Q000379:methods; D014792:Visual Acuity; D014825:Vocabulary