Discovery learning approaches to education have recently come under scrutiny (Tobias & Duffy, 2009) with many studies indicating limitations to discovery learning practices. Therefore, two meta-analyses were conducted using a sample of 164 studies: The first examined the effects of unassisted discovery learning versus explicit instruction and the second examined the effects of enhanced and/or assisted discovery versus other types of instruction (e.g., explicit, unassisted discovery, etc.). Random effects analyses of 580 comparisons revealed that outcomes were favorable for explicit instruction when compared to unassisted discovery under most conditions, d = -.38 (95% CI = -.44/-.31). In contrast, analyses of 360 comparisons revealed that outcomes were favorable for enhanced discovery when compared to other forms of instruction, d = .30 (95% CI = .23/.36). The findings suggest that unassisted discovery does not benefit learners, whereas feedback, worked examples, scaffolding, and elicited explanations do. …the average student will be unable to recall most of the factual content of a typical lecture within fifteen minutes after the end of class. In contrast, interests, values, and cognitive skills are all likely to last longer, as are concepts and knowledge that students have acquired not by passively reading or listening to lectures but through their own mental efforts (Bok, 2006, pp. 48-49).Over the past several decades, conventional explicit instruction has been increasingly supplanted by approaches more closely aligned with constructivist concepts of exploration, discovery, and invention (i.e., discovery learning), at least in part because of an appreciation of which learning outcomes are most valuable (Bok, 2006). Allowing learners to interact with materials, manipulate variables, explore phenomena, and attempt to apply principles affords them with opportunities to notice patterns, discover underlying causalities, and learn in ways that are seemingly more robust. Such self-guided learning approaches, like Piaget (1952;1965;1980) proposed, posit the child/learner at the center of the learning process as they attempt to make sense of the world. From an ecological perspective, people learn many complex skills without formal instruction through participation in daily activities and observation of others (Rogoff, 1990). Indeed, in cultures without institutionalized formal education, complex skills and modes of thought are learned in the absence of explicit, verbal teaching. Nonetheless, debate remains concerning the limitations of discovery learning (e.g., Bruner, 1961;Kirschner, Sweller, & Clark, 2006;Klahr & Nigam, 2004; Mayer, 2004;Sweller, Kirschner, & Clark, 2007; Tobias & Duffy, 2009). Pedagogical and cognitive concerns have led to some disagreement as to what constitutes effective discovery learning methods and how and when such methods should be applied. Two recent review papers (Kirschner, Sweller, & Clark, 2006; Mayer, 2004) have outlined some of the problems associated with various discover...