A Researcher Predicted That Music Training Would Enhance Young Children's

A researcher predicted that music training would enhance young children's spatial-temporalreasoning. 88 preschool children participated in the study. They were randomly assigned to oneof three conditions: 30 children received private music lessons, 29 children received computerlessons, and 29 children were the controls. A standardized test, the Wechsler Preschool andPrimary Scale of Intelligence (WPPSI) , was used to measure spatial-temporal reasoning beforeand immediately after the interventions. The WPPSI is evaluated positively in Buros MentalMeasurements Handbook and has been used in hundreds of studies on preschoolers' reasoningskills. All tasks were independently scored by two researchers blind to condition assignment.Interobserver reliability was r =.95. Significant improvement was found for the private musicgroup only. The researcher stated that this study demonstrates that music training produces longterm modifications in underlying neural circuitry, and improvement of this type may enhance thelearning of mathematics and science
-Rate evidence for reliability of the WPPSI:

A) Low: only one type of reliability is mentioned
B) Medium: interrater reliability is high, but no indication of other types of reliability evident
C) High: it is a standardized instrument with other evidence for reliability in the Buros Handbook, and high interrater reliability in this study
D) Medium because too few children were studied