The interactions between levels of learner prior knowledge and effectiveness of different instructional techniques and procedures have been intensively investigated within a cognitive load framework since mid-90s. This line of research has become known as the expertise reversal effect. Apart from their cognitive load theory-based prediction and explanation, patterns of empirical findings on the effect fit well those in studies of Aptitude Treatment Interactions (ATI) that were originally initiated in mid-60s. This paper reviews recent empirical findings associated with the expertise reversal effect, their interpretation within cognitive load theory, relations to ATI studies, implications for the design of learnertailored instructional systems, and some recent experimental attempts of implementing these findings into realistic adaptive learning environments.Keywords Expertise reversal effect . Prior knowledge . Expertise . Cognitive load theory .
Learner-tailored instructionAlthough advantages of individualized learner-tailored instruction have been recognized for long time and continue to be aspired (e.g., see VanLehn et al. 2007 for the most recent manifestation) it still remains a mainly unrealized dream for the majority of educators. Most instructional materials are designed in a fixed, one-for-all fashion, and by default, implicitly if not explicitly, assume novices as intended learners. Unavailability of suitable real-time (online) diagnostic assessment techniques has also impeded the development of learnertailored environments. Because of the involvement of many complex factors, issues of managing cognitive load by adapting instructions to individual learners, although recognized as important, have been mostly avoided by recent research projects in the field. On the other side, specific developmental projects in adaptive e-learning have been focused mostly on technical issues of tailoring instructional content to learner preferences, interests, choices, history of previous on-line behavior etc. and not based on fundamental cognitive characteristics of learners and evidence-based principles of instructional design.