Does doubled singing increase children’s accuracy? A re-examination of previous findings

Studies comparing solo singing to doubled singing indicate contrasting findings as to whether children evince superior solo or doubled singing. Previous findings have indicated: (a) superior solo singing; (b) superior doubled singing; or (c) no significant difference. A systematic review of studies meeting the inclusion criteria (N = 6) was undertaken to examine factors leading to these conflicting results. Next, a calculation of effect sizes that were unreported in previous research was based on published ANOVA tables, and expressed using Partial Eta-Squared. In direct comparisons of solo to doubled singing conditions, two studies reported that children sing more accurately in doubled singing; two studies reported more accurate solo singing; and two studies reported no significant difference by performance in the two conditions. The results indicate medium-to-large effect sizes in both directions. Several factors were enumerated to explain the contrasting findings: test administration procedures, song familiarity, vocal models, scoring methods, and teacher/researcher familiarity among the participants.