RESUMEN
CONTEXT: Over nearly two decades, a wealth of literature describing the various capabilities, uses and adaptations of virtual microscopy (VM) has been published. Many studies have investigated the effects on and benefits to student learning of VM compared with optical microscopy (OM). OBJECTIVES: This study statistically aggregated the findings of multiple comparative studies through a meta-analysis in order to summarise and substantiate the pedagogical efficacy of teaching with VM. METHODS: Using predefined eligibility criteria, teams of paired researchers screened the titles and abstracts of VM studies retrieved from seven different databases. After two rounds of screening, numerical and thematic data were extracted from the eligible studies for analysis. A summary effect size and estimate of heterogeneity were calculated to determine the effects of VM on learner performance and the amount of variance between studies, respectively. Trends in student perceptions were also analysed and reported. RESULTS: Of the 725 records screened, 72 studies underwent full-text review. In total, 12 studies were viable for meta-analysis and additional studies were reviewed to extract themes relating to learners' perceptions of VM. The meta-analysis detected a small yet significant positive effect on learner performance (standardised mean difference 0.28, 95% confidence interval 0.09-0.47; p = 0.003), indicating that learners experience marked knowledge gains when exposed to VM over OM. Variation among studies was evident as high heterogeneity was reported. An analysis of trends in learner perceptions noted that respondents favoured VM over OM by a large margin. CONCLUSIONS: Although many individual studies have reported non-significant findings in comparisons of VM and OM, the enhanced power afforded by meta-analysis revealed that the pedagogical approach of VM is modestly superior to that of OM and is preferred by learners.