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 TermsCentral Executive ChemistryChemical Equilibrium Cognitive Load TheoryCognitive Theory of Multimedia LearningContiguity PrincipleDual Coding TheoryElement interactivityEquilibrium shiftsEpisodic Buffer: Sub-system of working memory, controlled by the central executive,

that stores and integrates episodes across time (Baddeley, 2000). Extraneous Cognitive LoadGermane Cognitive LoadInteractivity PrincipleIntrinsic Cognitive LoadLong-term memoryModality PrincipleMultimediaMultimedia Principle

Phonological Loop: Sub-system of working memory where speech-based information is stored and manipulated (Baddeley, 1992)

SchemaSignaling PrincipleSocial Agency TheoryWorking 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