Cognitive challenges that are presented through the modification of established design principles may contribute to learning. One such challenge to the promotion of deeper processing is the Disfluency Effect. Specifically, disfluency manipulations in learning materials interfere with the perceptional fluency, which may in turn lead to better learning outcomes. This likelihood of reaching better learning outcomes through minor instructional modifications has led scholars to investigate the construct further. Accordingly, the effect of fluency modifications on learning outcomes, metacognitive judgments and cognitive load is investigated in the current study with a true experiment conducted with 292 undergraduate students who were assigned randomly to one of the six disfluency scenarios in a computer-based learning environment. Additional variables were also considered such as the working memory capacity, prior knowledge and cognitive load. Significant differences were observed with regard to the extraneous cognitive load, while there was no variation in the learning outcomes and metacognitive judgments in the experimental groups. Moreover, significant relationships were observed between cognitive load, the number of animations watched by the students and the learning outcomes. The results were interpreted in accordance with the approach in contemporary studies into the Disfluency Effect, and theoretical and practical implications are discussed.

Introduction

The contemporary opportunities provided by online connectivity facilitate individuals in carrying out many activities through digital devices. This has resulted in a situation in which individuals overlook their own cognitive abilities when carrying out simple operations, and to lose the ability to apply skills that cannot be delegated to machines (Alter, 2013). In order to overcome such a situation, it is important to face with cognitive difficulties for an active engagement. Such cognitive difficulties can be helpful also in instructional settings (Bjork, 1994), that is, they can be useful in breaking the study routines of the individual, varying the predictable nature of the instructional material and creating an unusual instructional pattern for effective learning (Bjork & Bjork, 2011). Challenges that slow down the learning process can revive longterm memory and improve the transfer of learning (Bjork & Bjork, 2011). One of the cognitive challenges is the Disfluency Effect, which is created through the interruption of fluency. According to Oppenheimer (2008) fluency is “the subjective experience of ease or difficulty associated with completing a mental task” (p.237). Fluency is not regarded as a separate cognitive process, but rather a facilitator of the cognitive processes. For instance, a frequently or recently viewed object is regarded as fluent, although there are several fluency types, such as perceptual, linguistic and memory-based (Alter & Oppenheimer, 2009b). Disfluency, on the other hand, can be defined as the subjective and metacognitive difficulties associated with cognitive tasks (Diemand-Yauman, Oppenheimer, & Vaughan, 2011). Disfluency is associated primarily with perceptual fluency, which is implemented through font manipulations (Alter & Oppenheimer, 2008b; 2009a). For instance, some scholars changed font type (French et al., 2013; Song & Schwarz, 2008) whereas some manipulated the font size (Rhodes & Castel, 2008; Strukelj, Scheiter, Nyström, & Holmqvist, 2016).