Il lavoro si è proposto di indagare le relazioni esistenti tra la metacognizione e la multimedialità, focalizzandosi in particolare sul ruolo che tali elementi possono avere sul processamento cognitivo. Partendo da un'analisi della teoria di Mayer relativa all'apprendimento multimediale, e da un'attenta disamina della letteratura recente riguardante il rapporto tra metacognizione e multimedialità, sono stati progettati tre percorsi di ricerca. Il primo consiste in un'analisi di dell'uso delle illustrazione nei testi scolastici italiani analisi volta a far emergere modelli impliciti dell'utilizzo della multimedialità. Questo primo progetto di ricerca comprende anche una seconda parte, strutturata sotto forma di interviste, volta a studiare più direttamente le concezioni ingenue di diversi sottocampioni di soggetti. Le seconda ricerca è volta a verificare il livello di accordo spontaneo che studenti universitari possono dimostrare rispetto ai principi multimediali ipotizzati da Mayer. La terza parte sperimentale, invece, si è soffermata sull'analisi del ruolo e degli effetti della metacognizione e delle differenze individuali nella fruizione di presentazioni multimediali. I risultati delle ricerche sono stati discussi anche confrontandoli con i dati della più recente letteratura di settore. / The present work was aimed at exploring relations between metacognition (declined in metacogntion knowledge, monitoring and control) and multimedia, focusing particularly on the role that those elements have on cognitive processing. Starting from a theoretical analysis of Mayer's model of multimedia learning, and from a detailed examine of the recent literature concerning metacognition and multimedia, we devised 3 experimental projects. The first one was an analysis of instructional illustrated books, intended to discover embedded beliefs about multimedia. This project included also an interview study to directly investigate people naïve conceptions. The second research was aimed to investigate if cognitive principles underlying multimedia learning are counterintuitive asking students to rate the effectiveness of Mayer's own experimental materials. The third part was focused on the role of active metacognition and individual differences in the fruition of a multimedia presentation. Results from the three studies were discussed and compared with existing literature.

This study attempts to discern if geologic time is a threshold concept for student understanding of evolutionary theory. A threshold concept enables the learner to unpack other concepts because of its importance in thought construction. In this study three teachers and ten sections of biology were investigated from the same high school. Each teacher used the same activities, in the same sequence, and with identical evaluation methods. Students in the treatment group covered a unit on geologic time prior to completing course work on evolutionary theory. Student misconceptions in both control and treatment groups were assessed using a composite concept inventory administered post and prior to the study. Statistical analysis conducted revealed no statistical evidence to support the contention that the treatment method was more effective than traditional methods of teaching evolution. It was found that students agreed significantly more with evolution post study in both treatment and control groups.