The suitability of the DTVP-2 as a measurement instrument for 5 years and 6 months to 5 years and 11 months English-speaking children in South Africa

[摘要] English: As there is limited comprehensive visual perceptual skills test that has beenstandardised on a representative South African population, occupational therapists inSouth Africa make use of measurement instruments standardised in other countriesto measure children's visual perceptual skills. A measurement instrument frequentlyused by SA OTs, the DTVP-2, is a reliable and valid test for the population on whichthe test was standardised. However, the DTVP-2's suitability is questioned in a crossculturalsetting, specifically the SA population.The aim of the study was to investigate the suitability of the Developmental Test ofVisual Perception �?2nd edition (DTVP-2) as a measurement instrument for 5 yearsand 6 months to 5 years and 11 month English-speaking boys and girls from the Cityof Tshwane, South Africa.A quantitative, descriptive, observational study was conducted. One-hundred andthirty four (134) study participants were recruited by means of stratified randomsampling from English Language of Learning and Teaching schools located withinthe four educational districts in the urban-suburbs of the City of Tshwane. A selfadministeredscreening questionnaire was used as a screening method to establishchildren's eligibility for inclusion in the study, as well as for parents/caregiver to provide informed consent. Children of parents/caregivers who returned thequestionnaires were assessed with the DTVP-2. The DTVP-2's motor-enhancedsubtests were administered according to the prescribed method, while each of themotor-reduced subtests of the DTVP-2 was administered with an adapted method ofnot implementing the ceiling rule.Results of the study yielded that the SA study sample's scores differed to theAmerican normative sample. The position in space- and visual closure subtestsyielded more accurate results when the ceiling rule was not implemented. It wasestablished that the DTVP-2 was unbiased for gender, with the exception of figureground,when scored according to the prescribed method. The DTVP-2 displayedoverall acceptable reliability, however the individual subtests of visual closure, visualmotorspeed and form constancy was found to be unreliable. A Rasch analysisrevealed that figure-ground and form constancy of the motor-reduced subtestsmeasured a single construct and the four motor-reduced subtests of the DTVP-2exhibited distorted item difficulty and –linearity resulting in misapplication of theceiling rule.It is concluded that the DTVP-2 should be used with caution to measure 5 years and6 months to 5 years and 11 months English-speaking children's visual perceptualskills and care must be taken when interpreting and conveying scores to parents andother health care professionals. It is recommended that South African occupationaltherapists adjust and/or be sensitive in their assessment procedures in order toinform evidence-based practice.

[发布机构] University of the Free State