highly significantp < 0.001
Most importantly, skills in performing opera showed a significant increase from pre-intervention ( M = 65.3, SD = 8.2) to post-intervention ( M = 78.9, SD = 7.1), with a t-statistic yielding a statistically highly significant difference, t (198) = 14.27, p < 0.001, with a large effect size, d = 1.73.