1. SECTION I INTRODUCTION Statement of the Problem (no heading) Purpose of the Study Significance of the Problem Theoretical Rationale Four theories provide the framework for the proposed study. The Working Memory Theory originally proposed by Baddeley and Hitch (1974) sets the cognitive infrastructure for Cognitive Load Theory (CLT), proposed by Sweller (1988). Mayer’s (2001) Cognitive Theory of Multimedia Learning (CTML) outlines a cognitive context for multimedia learning interventions, and a Social Agency Theory of Multimedia Learning proposed by Mayer et al (2003) and Moreno (2001), lends additional rationale for the use of screencasts as multimedia learning vehicles. Working Memory Theory During the execution of a complex task it is necessary to hold information in a temporary storage space. The system used to describe this storage space is referred to as working memory (Baddeley and Hitch, 1974). Working memory is an extension of the short-term memory concept proposed by Atkinson and Shiffrin (1968). Similar to short-term memory, working memory is limited in its capacity to store information (Miller, 1956). Unlike the unitary short-term memory model, the initial working memory model contained three subsystems that work together as a functional unit to carry out processing tasks such as learning, reasoning and comprehension (Baddeley, 1996). The first sub-system is called central executive. The central executive serves as the supervisory system that controls flow of information in and out of the other two sub-systems: the phonological loop and the visuospatial sketchpad. The phonological loop is responsible for the storage and rehearsal of speech-based information, while the visuospacial sketchpad stores and manipulates visual information. Because the phonological loop and the visuospatial sketchpad are storage systems supervised and controlled by the central executive, they are referred to as slave systems (Baddeley and Hitch, 1974). Baddeley (2000) expanded upon the initial working memory model by proposing a fourth subsystem: the episodic buffer. The episodic buffer, the third slave system, is responsible for the temporal coordination of verbal, spatial and visual information. The episodic buffer has a limited ability to link information, and is thought to have connections to long-term memory. Cognitive Load Theory Cognitive Load refers to the impact or load new information has on working memory. Much like the working memory theory, the roots of Cognitive Load Theory (CLT) can be traced back to Miller’s (1956) hypothesis that working has a very limited capacity. Initially proposed by Sweller (1988), Chandler and Sweller (1991) further developed CLT as a framework for instructional designers to follow when helping learners optimize performance during instruction. Since its initial conception, CLT has evolved through the work of the original authors and other researchers who aim to optimize the limited capacity of working memory during instruction (e.g. Ayers, 2006; Chandler & Sweller, 1992; Sweller & Chandler,1994; Mayer, Moreno, Boire & Vagge, 1999; Brunken, Plass & Leutner, 2004; van Merriënboer, Kirschner & Kester, 2003; Mayer & Moreno, 2003; DeLeeuw & Mayer, 2008). Chandler and Sweler (1991) differentiate between three types of cognitive load: extrinsic, intrinsic and germane. While extrinsic cognitive load is function of how information is presented, intrinsic cognitive load relates to the natural complexity that a specific knowledge domain offers. Once extrinsic and intrinsic cognitive load are accounted for, germane cognitive load is devoted to using available working memory space to process information, build schema and facilitate meaningful learning (Mayer & Moreno, 2003). Originally seen as the only static cognitive load subsystem, the current study builds on recent research into intrinsic cognitive load aimed at making complex domains, such as chemistry, more accessible by decreasing the overall element interactivity. The specific mechanism encourages schema formation a pre-training session (Clarke, Ayers, & Sweller, 2005; Mayer & Moreno, 2003; Mayer, Mathias, & Wetzell, 2002). In doing this, as the learner develops partial prior-knowledge, individual elements can be chunked into schema. Subsequently, the overall element interactivity during the second phase of instruction is decreased (Kalyuga, Ayers, Chandler and Sweller, 2003). Cognitive Theory of Multimedia Learning Developed by Mayer (1997), a Cognitive Theory of Multimedia Learning (CTML) represents an integration of working memory theory and CLT. Additionally, CTML draws on the Dual Coding Theory (Clark & Pavio, 1991; Pavio, 1986), which builds upon Baddeley’s visuospatial sketchpad and phonological loop model, by proposing that visual and verbal information enter and are process along different channels in the working memory. Thus, given working memory foundation, using CLT as a framework for multimedia instructional design limits the potential for cognitive overload of either channel (Mayer, 2001). Multimedia is defined as the presentation of information using both words and pictures. Keeping in mind the above theories, a CTML embodies three major assumptions. First, the dual-channel assumption states that visual and verbal information is processed via separate channels in the working memory. Next, the limited capacity assumption notes that each channel in the working memory is limited in its ability to process new information. Finally, the active processing assumption posits that the working memory is actively trying to create coherent mental representations from information processed through each channel. With the three over arching CTML assumptions, Mayer (2005) outlines twenty-five numerous design principles meant to assist instructors in creating multimedia interventions that are sensitive to cognitive overload. Specific to the proposed study, five design principles (multimedia, contiguity, modality, signaling, & interactivity) have been effective at helping chemistry students negotiate the many complexities of the subject (Kozma, Russell, Jones, Marx, & Davis, 1996). Social Agency Theory of Multimedia Learning Considered an extension of CTML, a Social Agency Theory of Multimedia Learning provides additional rationale for the use of a multimedia tool, specifically screencasts, in this study. According to this theory, multimedia learning environments can be constructed, using verbal and visual cues, in such a way that the learner develops a partial social relationship with the computer interface. Once the partnership is established, learners can rely on basic human-to-human rules to cooperate and make sense out of the information presented (Grice, 1975; Mayer, et al., 2003; Moreno et al., 2001). Because screencasts involve the recording and propagation of all screen activity, including mouse movements, digital annotations, and voice, they embrace a structure that is consistent with a CTML and the social agency implications that arise from specific multimedia design. Using the theory of social agency in multimedia learning as a lens, three more instructional design principles (personalization, image, & voice) surface. In conjunction with the five chemistry specific principles discussed as part of a CTML, these three design principles further strengthen the theoretical framework of this study as it applies to multimedia. Summary The theoretical rationale for the current study originates from the limited, yet multi-faceted model of working memory. CLT, in coordination with the design principles and social agency implications that have emerged from a CTML, arm instructional designers with theory that validates the use of multimedia learning tools in the classroom. With work and design recommendations that have emerged from these theories, the current study aims to study the effects of using screencasts, a relatively new multimedia learning tool, as a way to decrease the intrinsic cognitive load associated with the complex chemistry knowledge domain. Background and Need Successful completion of a course in chemistry is a requirement for the majority of high school students in the United States. Over 60 % of all US public schools offer a Chemistry or Advanced Placement Chemistry program (College Board, 2006). Since 1998, the number of students taking the AP Chemistry Exam has risen from 1 million, to approaching 2.7 million in 2008 (College Board, 2008). Moreover, completing a post-secondary course in chemistry is a necessary first step for most careers in science or health (Webster, 2009). Specifically, the Medical College Admissions Test (MCAT) strongly emphasizes chemistry knowledge and problem solving skills as they apply to chemistry phenomena (AAMC, 2009). Despite the large number of students taking chemistry nationwide and the inclusion of chemistry as a pre-requisite for the many careers in the health sciences, a significant drop in the number of students choosing chemistry as an undergraduate major has been noted over the last three decades (Lowe, 1968; Hammond, 1977; Smithers, 1989; Habraken, 1989; Stevenson, 1995; Roberts, 1995). Keeping with this trend, understanding the mechanisms behind student performance and perception of chemistry has been an active area of research over the past five years (Lewis, & Lewis, 2007; Tai, Sadler, & Loehr, 2005; Tai, Sadler, & Mintzes, 2006). De Vos et al. (1993, 1994) argue that this downward trend is catalyzed by growing level of student awareness of a disconnect between traditional high school chemistry curriculum, and current movements in modern chemical research, technology and teaching pedagogy. This hypothesis is corroborated Birk and Foster (1993) who claim that the traditional didactic, lecture method of teaching, pervasive in American schools, results in very little substantial learning, and therefore low performance. Moving beyond the traditional method of instruction, incorporating multiple teaching strategies into the chemistry classroom will allow instructors access to the cognitive strengths of all students (Francisco & Nicoll, Date, 2000). Chemistry educators and researchers will be challenged to familiarize themselves with the cognitive sciences, grounding pedagogy in useful theory and relevant to the known learning differences in the subject (Herron & Nurrenbern, Date, 2000). This strong relationship between chemistry education and human cognition is well documented in the literature. Not only is chemistry identified as a subject that is difficult to learn, the simultaneous conceptual and algorithmic thinking required further intensifies the complex problem solving and critical reasoning skills needed for success. The intrinsic complexity of chemistry creates many student misconceptions that hinder performance (Anderson, 1990; Gable, 1999; Krajcik, 1991; Nakhleh, 1992; Stavy, 1995; Wandersee, Mintzes, & Novak, 1984). Specifically, of the 96,458 secondary students who took the Advanced Placement Chemistry Exam last year, less 60% received a score that would be deemed passing ( 3) by colleges and universities nationwide (College Board, 2008). From a cognitive perspective, it is argued that the need coordinate and assimilate concepts or elements into knowledge constructs is the primary generator of information complexity in a difficult subject such as chemistry (Paas et al., 2003; Sweller & Chandler, 1994). Simple tasks are said to have low element interactivity, and contain elements that can be learned in isolation, whereas complex tasks contain elements that must be learned in concert with one another. A subject is complex, not because of the number of elements to be learned, but the need to simultaneously assimilate the many elements before meaningful learning can occur (Sweller, 1999; Sweller & Chandler, 1994). Element interactivity is a term that comes from Cognitive load theory (CLT) (Sweller, 1988; Chandler & Sweller, 1991). The central tenant of CLT is that the human cognitive architecture contains a working memory that is limited in its capacity to process information (Miller, 1956; Baddeley and Hitch, 1974). CLT theory assumes that learning occurs through this limited working memory and an unlimited long-term memory that is structured into a hierarchy of knowledge constructs or schemas (Baddeley, 1996; Baddeley and Hitch, 1974; 1992; Chi, Glaser, & Rees, 1982; Larkin, McDermott, Simon, & Simon, 1980; Miller, 1956; Newell & Simon, 1972; Simon, 1974). By designing instruction in a way that is sensitive to the limited capacity of the working memory, cognitive overload can be avoided and meaningful learning can occur (Sweller & Chandler, 1991; Chandler & Sweller, 1992; Sweller & Chandler,1994; Sweller, 1999; Sweller et al, 1998). Chandler and Sweller (1991) identified three different types of load that place processing demands on the working memory: intrinsic, extrinsic and germane. Intrinsic load is caused by the natural complexity of material to be learned, and as discussed above, changes in direct proportion to the level of element interactivity required in a learning task (Paas et al., 2003; Sweller & Chandler, 1994). Extraneous load relates to the manner in which information is presented. When a learner devotes working memory space to a task not directly related to the learning task, extraneous load is increased (Carlson, Chandler & Sweller, 2003). Germane load refers to the load created during schema formation and automation. Germane load is often considered to be useful load on working memory, while intrinsic and extraneous load are thought of as roadblocks to meaningful learning (Paas & van Merriënboer, 1994). CLT researchers argue that the three sources of cognitive load are additive. For example, if extrinsic and/or intrinsic cognitive are too high, the potential for cognitive overload in the working memory exists. Likewise, if the sum of extrinsic and intrinsic load is reduced, more germane load can be allocated toward active processing in the working memory (Ayers, 2006). CLT theory suggests that when complex information, such as that presented during chemistry a chemistry lesson, minimizing extrinsic and intrinsic cognitive load allows for greater working memory allocation to germane load, and thus more meaningful learning (Carlson, Chandler, & Sweller, 2003). Due to the intimate relationship between extraneous cognitive load and instructional design, much of the past CLT research has focused on decreasing extraneous load. Instructional interventions that have been effective at reducing extrinsic load include worked examples, establishing goal-free activities, imaging strategies, and interventions designed around the completion, modality and redundancy effects (Ginns, 2005; Kalyuga, Chandler, Touvinen, & Sweller, 2001; Sweller, 1999; Cooper, Tindall-Ford, Chandler, & Sweller, 2001; van Merrienboer, Schuurman, de Croock, & Paas, 2002; Brunken & Leutner, 2001; Mayer & Moreno, 2003; Sweller, 1999). Related to the knowledge domain of the proposed study, significant research has been done in using visual models as a tool to decrease the extraneous load of teaching inorganic and organic chemical nomenclature (Carlson, Chandler, & Sweller, 2003). The additive nature of extrinsic and intrinsic load has been a deceiving equation for CLT researchers. Unlike extrinsic load, research into instructional design has operated from the understanding that the intrinsic load of a subject cannot be decreased when learner prior knowledge is controlled for. That is, element interactivity is inherent to the material and the learner’s prior knowledge and is not a function of the environment or presentation mode (Sweller & Chandler, 1994; Chandler & Sweller, 1996; Paas et al., 2003; Pollock, Chandler, & Sweller, 2002). Subsequently, optimizing germane load by reducing only the extraneous load of the instructional environment has the been a major theme in the CLT literature over the past decade (Ayres & Sweller, 2005; Low & Sweller, 2005; Mayer, 2005a; Mayer, 2005b; and Mayer & Moreno, 2003). Recently, CLT research has begun to shift its attention towards intrinsic cognitive load. Kalyuga, Ayers, Chandler and Sweller (2003) noticed that as a learner develops content expertise, the element activity of a task decreases as the interactions become incorporated into long-term memory schema. Thus, if a learner possesses long-term memory schema for a particular task, he or she is able to treat multiple interacting elements as single entities or chunks, resulting in a decrease of the overall element interactivity (Ayers, 2006). For example, studies have shown that segmenting instruction into part-whole tasks where instruction is broken up into simple, then complex sequences has shown promising results as a schema acquisition method. (Mayer & Chandler, 2001; van Merrienboer, Kester, & Paas, 2006). Pre-training, where learners receive initial instruction before a final presentation mode, has also been effective at building prior knowledge and thus decreasing intrinsic cognitive load. In particular, pre-training as a schema acquisition tool has shown specific promise when employing a multimedia intervention (Clarke, Ayers, & Sweller, 2005; Mayer & Moreno, 2003; Mayer, Mathias, & Wetzell, 2002). Pollack, Chandler, and Sweller (2005) conducted an effective hybrid of the part-whole and pre-training modules by designing a strategy called the isolated-elements procedure. This procedure involved splitting instruction into two phases. During the first phase, each element is presented as an isolated entity, and during the second phases, integrated tasks are presented to the learner. Much of the recent CLT research aimed at lowering the intrinsic cognitive load of complex material harnesses a multimedia learning tool (Mayer & Moreno, 2003). CLT is easily studied in the context of multimedia learning as the use of multimedia involves processing information from different sensory modalities in the working memory. At its core, a multimedia instructional message refers to any form of communication containing words and pictures intended to foster learning (Mayer, 2001). Thus, a central challenge to multimedia instructional designers is to craft interventions that are sensitive to the cognitive load on working memory. Given the utilization of two different learning modalities, a potential for cognitive overload of working memory exists (Clark, 1999; Sweller, 1999; van Merrienboer, 1997) A process theory meant to supplement CLT was introduced by Mayer (2001) as the Cognitive Theory of Multimedia Learning (CTML). Central to the relationship between CLT and the CTML are three basic assumptions regarding human cognitive architecture: the dual-channel, limited capacity, and active processing assumptions. The dual-channel assumption states that the working memory possesses separate channels for processing visual and auditory information (Pavio, 1986). The limited capacity assumption states that the working memory is limited and capable of cognitive overload (Chandler & Sweller, 1991). The active processing assumption states that learners are actively attempting to make sense of instruction by organizing and selecting information into coherent mental representations (Mayer, 2001). Specific to instruction, the CTML outlines numerous design principles to assist the educator in creating a multimedia learning environment that is sensitive to cognitive overload (Mayer, 2001). Related to the proposed study, Mayer (2005) outlines five, out of the twenty-five research based design principles that are most relevant to the complex and symbolic chemistry learning environment: the multimedia principle, contiguity principle, modality principle, signaling principle, and interactivity principle. The multimedia principle states that learning from words and pictures results in more meaningful learning that words alone. The contiguity principle indicates that students learn more when words and pictures are presented close to one another both spatially and temporally. The modality principle directly relates to the dual channel assumption described above. It notes that students learn more from animation and narration, rather than from animation and on-screen text. The signaling principle indicates that improved learning occurs when guidance is provided, and the interactivity principle states that deeper learning occurs when students can control the order and pace of a specific multimedia presentation (Mayer, 2001). As previously noted, learning chemistry is a complex process, possessing a high intrinsic cognitive load (Anderson, 1990; Carlson, Chandler & Sweller, 2003; Gable, 1999; Krajcik, 1991; Nakhleh, 1992; Stavy, 1995; Wandersee, Mintzes, & Novak, 1984). Applying the five chemistry specific multimedia design principles outlined above to practice could make an important contribution to helping students negotiate the complexity of learning chemistry (Gable, 1998; Gable & Bunce, 1994; Nakhleh, 1992). For example, equilibrium is widely known as one of the most complex topics in a chemistry curriculum (Banerjee, 2004). Specifically, the study of equilibrium shifts, a topic used to describe the dynamic nature of chemical reactions, contains a very high level of element interactivity (Crippen & Brooks, 2005; Tyson & Treagust, 1999). Research indicates that applying the five multimedia design principles towards the teaching of equilibrium shifts results in increased student understanding of this difficult concept (Kozma, Russell, Jones, Marx, & Davis, 1996). Despite the promising link between the complexity of teaching chemistry and the CTML outlined above, Mayer (2005) stresses that an urgent need exists for more research in the area of multimedia learning in chemistry. Mayer’s comments are corroborated by Richardson (2009) who notes that next generation of learners are dependent upon, and growing within, a society that uses multimedia resources more than ever before. Within the past few years, screencasts have emerged as useful multimedia learning tools. Screencasts are recordings of all computer on-screen activity including mouse movements, clicks and audio, that can be saved as a video file and propagated online to an intended audience (Bergman & Sams, 2008; Peterson, 2007; Richardson, 2009). Given the five multimedia design principles specific to learning chemistry, the online, audio and visual nature intrinsic to a screencast could be a promising learning tool for chemistry students. For example, students could play and replay specific aspects of a screencast tutorial while being strategically guided by the instructor, harnessing both the signaling and interactivity principles. Teachers could include voice narration to accompany diagrams and add digital annotations using tablet pen technology to scaffold problem-solving techniques for students. Both of these examples employ aspects of the multimidea, continguity and modality principles (Mayer, 2001). The use of screencasts in education is also supported by the Social Agency Theory of Multimedia Learning (Mayer et al, 2003; Moreno et al, 2001). Viewed as an enhancement to the CTML, social agency theory posits that multimedia learning environments can be designed to encourage learners to operate under the assumption that their relationship with the computer is a social one, in which the conventions of human-to-human relationships exist (Reeves & Naas, 1996). Once this social partnership exists, learners can rely on basic social rules that guide their interaction with the multimedia learning environment (Mayer, et al., 2003). Mayer (2001) outlines three instructional design principles that rely of social agency theory as their theoretical infrastructure: the personalization, voice and image principle. The personalization principle states that students learn more when narration is conversational rather than formal. The voice principle notes that students learn more when the accent of the narrator is not a foreign one. The image principle indicates that the student does not necessarily learn more when the narrators image is visible on the screen. The instructor narrated aspect of a screencast aligns well with the personalization and voice principles. Additionally, the nature of a screencast recording embraces the image principle in that, by definition, it is a recording of on-screen activity, rather than a video image recording of the instructor (Richardson, 2009). Despite the promising characteristics of screencasts as multimedia interventions to address the complexity of learning chemistry, a review of the research literature revealed no significant studies that tested the efficacy of screencasts in classroom (Peterson, 2007). As CLT research continues to more thoroughly address intrinsic cognitive load, a clear need exists for research into the efficacy of using new multimedia learning tools such as screencasts to improve learning in complex knowledge domains. The purpose of the proposed study is to examine the efficacy of instructor narrated and digitally annotated screencasts as a pre-training tool to reduce the intrinsic cognitive load of chemistry instruction for advanced placement high school chemistry students. This study will build upon the multimedia pre-training work done by Clarke, Ayers, and Sweller (2005), but will harness a modular, rather than part-whole approach. In this approach, the multimedia intervention (screencast) will be used to present a simplified version of a lesson before the entire instructional phase is implemented. Gerjets, et al. (2004) argue that this modular approach is more effective when negotiating the intrinsic load of complex learning environments particular to those seen in learning chemistry. Specifically, pre-training will focus on building partial long-term memory schema in a unit involving the study of equilibrium shifts, the topic identified in the research as possessing the highest intrinsic cognitive load (Banerjee, 1996; Treagust & Tyson, 1999). Research Questions Definition of Terms Central Executive Chemistry Chemical Equilibrium Cognitive Load Theory Cognitive Theory of Multimedia Learning Contiguity Principle Dual Coding Theory Element interactivity Equilibrium shifts Episodic Buffer: Sub-system of working memory, controlled by the central executive, that stores and integrates episodes across time (Baddeley, 2000). Extraneous Cognitive Load Germane Cognitive Load Interactivity Principle Intrinsic Cognitive Load Long-term memory Modality Principle Multimedia Multimedia Principle Phonological Loop: Sub-system of working memory where speech-based information is stored and manipulated (Baddeley, 1992) Schema Signaling Principle Social Agency Theory Working memory: A limited and multifaceted information storage and processing system (Baddeley, 2000) Visuospatial sketchpad: Sub-system of working memory where visual information is stored and manipulated (Baddeley, 1986). Summary