“…In effect, both principles entail that the presentation of extraneous information should be avoided, because it hampers learning compared to instructional materials in which this information has been eliminated. For instance, a negative effect of extraneous information on learning has been shown to occur when multimedia learning materials are enriched with interesting and entertaining information (i.e., seductive details; Harp & Mayer, ; Lehman, Schraw, McCrudden, & Hartly, ; Mayer, Heiser, & Lonn, ; Moreno & Mayer, ; Rey, ; Sanchez & Wiley, ), when information on related systems is presented when learning about a specific system (Mayer, DeLeeuw, & Ayres, ), or when mismatching pictorial information is provided when learning word definitions (De Nooijer, Van Gog, Paas, & Zwaan, ; Hald, Van den Hurk, & Bekkering, ; Rop et al, , ). Moreover, the effect has been demonstrated when text accompanying pictures or animation is presented in both spoken and written form (e.g., Craig, Gholson, & Driscoll, ; Mayer et al, ; but see Mayer & Johnson, ; Yue, Bjork, & Bjork, ), when self‐containing diagrams are accompanied by textual explanations (Bobis, Sweller, & Cooper, ; Chandler & Sweller, ) and when unnecessary details and examples are added to learning materials (e.g., Mayer, Bove, Bryman, Mars, & Tapangco, ; Reder & Anderson, ).…”