Malaysian Online Journal of Instructional Technology (MOJIT) December 2005 ISSN 1823:1144
Vol. 2, No.3, pp 106-117
Recent Advances in Cognitive Load Theory Research: Implications for Instructional Designers Toh Seong Chong Centre for Instructional Technology and Multimedia Universiti Sains Malaysia 11800 Pulau Pinang
[email protected] ABSTRACT The cognitive load theory (CLT) is widely accepted by instructional designers, since it provides a solid theoretical foundation in designing guidelines for constructing e-learning content in a way that enhances learning. According to this theory, learning will be impaired if the learning content causes a cognitive overload. Since the capacity of the working memory is very limited, the theory assumes that presenting different sources of information in the same modality (for example, only visually) easily results in a split-attention effect, which leads to poor learning performance. To avoid this, a method suggested by the cognitive load theory is to present information in different modalities (for example, auditory text plus visual displays). Recent advances in the cognitive load theory research community have contributed significantly towards the instructional design of the interaction between information structures and the human cognitive architecture. The nuances of this theory are continually evolving and have spurred a plethora of research in multimedia learning. This article reports the recent developments within the framework of the cognitive load theory in the context of several experiments conducted at the Centre for Instructional Technology and Multimedia, USM. Several applications resulting from recent advances of this theory are discussed. INTRODUCTION In the field of instructional technology, there has been an increased interest and focus on the effectiveness and efficiency of various instructional design strategies. Some of the most important breakthroughs in this regard have come from the discipline of cognitive science, which deals with the mental processes of learning, memory and problem solving. Cognisant to this trend are questions and criticisms about the design of online course content and its bearing on learning. Many factors may affect the effectiveness of various instructional design techniques and courseware developers may be hard-pressed to find specific guidelines based on research findings to assist them. Given that most, if not all online, courses contain content in the form of texts, images or multimedia, it is important for these research findings to be extracted at a broader level and deployed in practical day-to-day tasks such as instructional design and development. A comprehensive review of research literature over a period of time can provide a rich and comprehensive set of guidelines. Furthermore, by reviewing a set of literature as a whole, one can not only extract specific conditions where techniques will or will not work, but also if the implementation of several techniques conflict with or cancel out the effects of one another. Therefore, the goals of this paper are threefold. Firstly, it is to review, analyse and synthesise theoretically grounded educational psychology research over the past 20 years. Secondly, it is to derive specific instructional design techniques and related conditions. Thirdly, it is to map out the intricate relationships among these techniques; thereby developing a guide for courseware developers. By providing these perspectives to instructional designers, they can make more informed decisions about developing instructionally sound materials.
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THE COGNITIVE LOAD THEORY (CLT): BASIC ASSUMPTIONS Although there are many theories that are related to mental processes and learning, the majority of recent research has directly or indirectly substantiated the tenets of the cognitive load theory CLT) which asserts that the limitations of the working memory should be considered in instructional design. It is based on the assumption that a learner has a limited processing capacity and proper allocation of mental resources is necessary. Otherwise, devoting mental resources to activities not directly related to schema construction and automation may inhibit one’s learning. Learning consists of schema construction and automation. The CLT (Sweller, 1988; 1994) focuses on how constraints on the human working memory help determine what kinds of instruction are effective. It describes learning structures in terms of an information processing system involving the long-term memory, which effectively stores all of our knowledge and skills on a more-or-less permanent basis and the working memory, which performs the intellectual tasks associated with consciousness. Information may only be stored in the long-term memory after first being attended to, and processed by, the working memory. The working memory The designated short-term memory (e.g., Miller, 1956) is now more commonly referred to as the working memory (e.g., Baddeley & Hitch, 1974). This reflects the change in emphasis from a holding store to the cognitive system’s processing engine. The working memory can be equated with consciousness in that the characteristics of our conscious lives are the characteristics of the working memory. The most commonly expressed attributes of the working memory are its extremely limited capacity, discussed by Miller (1956) and its extremely limited duration, discussed by Peterson and Peterson (1959). In fact, both of these limitations apply only to novel information that needs to be processed in a novel way. Well-learned material, held in the long-term memory, suffers from neither of these limitations when brought into the working memory (Ericsson & Kintsch, 1995). Although the working memory was initially conceptualised as a unitary concept, it is now more commonly assumed to consist of multiple streams, channels or processors. This assumption was pioneered by Baddeley (Baddeley, 1992; Baddeley & Hitch, 1974) who divided the working memory into a visuospatial sketchpad for dealing with two-dimensional diagrams or three-dimensional information, a phonological loop for dealing with verbal information and a central executive as a coordinating processor (see Figure 1).
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Central Executive - links the slaves systems and long-term memory. It is also responsible for making plans and selecting strategies.
Visuospatial sketchpad - stores and manipulates visual and spatial information. Located at right hemisphere of the brain
Episodic buffer - a slave system, which encodes, integrates and retrieves information in the form of conscious awareness
Visual semantics
Phonological loop - is a slave system that stores and manipulates auditory information. Located at left hemisphere of the brain
Language
Episodic LTM
Figure 1: The working memory model (Baddeley’s, 2000)
A major consequence of the limitations of the working memory is that when faced with new, high element interactivity material, we cannot process it adequately. We invariably fail to understand new material if it is sufficiently complex. In order to understand such material, other structures and other mechanisms must be used. Processing high element interactivity material requires the use of the long-term memory and learning mechanisms. Thus according to the CLT, one should encourage learning activities that minimise processing and/or storage that is not directly relevant for learning in order to avoid taxing the working memory’s limited capacity. In order to really comprehend this assertion more deeply, three types of load have to be differentiated (Sweller, Van Morriℑboer and Pass, 1988). See Figure 2.
Total Cognitive Load Intrinsic Cognitive Load
Extraneous Cognitive Load
Figure 2: Intrinsic and extraneous cognitive loads
The intrinsic load refers to the complexity of the learning material that a learner intends to mentally learn. It is dependent on the intrinsic nature (difficulty level) of the learning material and also on the learner’s amount of prior knowledge. Prior knowledge is included in this definition because the size of meaningful information “chunks” that a learner can handle without taxing his or her limited working memory capacity is dependent upon it. A learning task that might be complex for a beginner may, on the other hand, be simple for an expert. 108
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The germane load refers to demands placed on the working memory that are imposed by mental activities that contribute directly to learning. In the case of worked examples, self-explanatory activities would be considered as a germane load. Self-explanations refer to a learner’s effort in gaining an understanding of a solution rationale, such as trying to find the domain principle underlying a certain solution step.
The extraneous load refers to mental activities during learning that do not contribute directly to learning. Similar to the germane load, what constitutes the extraneous load depends on the goal of the learning task. For example, when problem solving schemata should be acquired, the extraneous load is imposed if instructional materials contain texts and graphics that are difficult to integrate with each other. Learners may use much of their working memory to try to establish coherence between the two information sources. As a result, little or no cognitive capacity remains for the germane load, especially if there is also a substantial intrinsic load because of the learning material itself.
The redundancy effect occurs when the removal of a redundant source of information enables limited mental resources to be directed to appropriate sources of information for schema construction and automation. It thus reduces the risk of a cognitive overload. Thus when we consider the three loads together, it is important not to induce a high extraneous load (that is, a load due to activities unrelated to the learning process), especially when it is coupled with a high intrinsic load. This is because extraneous and intrinsic loads may leave only a modicum or “no room” for the germane load.
Schema constructions are domain-specific knowledge structures which categorise multiple elements of information as a single element and determine appropriate actions. Hierarchically organised, schemas reduce the load on the working memory and enable people to hold a presumably unlimited number of elements of information in the long-term memory. Changes to schemas also result in changes in problem-solving strategies. Specifically, novice learners tend to work backwards from a goal, using means-ends analysis and sub-goaling. As schemas develop, learners shift to a strategy of working forward from the initial problem state to the goal. This is a less resource demanding, expert strategy. Automation occurs when operating schemas is no longer controlled, in other words, no longer requiring conscious effort and related working memory resources. THE COGNITIVE THEORY OF MULTIMEDIA LEARNING More recently, multimedia learning has become a focus of research. The guru of multimedia learning research is Professor Richard Mayer from the University of California at Santa Barbara. He called it the Cognitive Theory of Multimedia Learning. Mayer has based the majority of his multimedia work on an integration of Sweller’s cognitive load theory (Chandler & Sweller, 1991; Sweller, 1999), Pavio’s dual-coding theory (Clark & Paivio, 1991; Paivio, 1986), and Baddeley’s working memory model (1992, 1999). This theory is based upon three primary assumptions (Mayer, 2001): 1. Visual and auditory information/experiences are processed through separate and distinct information processing “channels”. 2. Each information processing channel is limited in its ability to process information/experiences 3. Processing information/experiences in channels is an active cognitive process designed to construct coherent mental representations. Further, this model is activated through five steps (or summarised as Selection, Organise and Integrate), namely: 109
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Selecting relevant words for processing in the verbal working memory. Selecting relevant images for processing in the visual working memory. Organisation of selected words into a verbal mental model. Organising selected images into a visual mental model. Integrating verbal and visual representations as well as prior knowledge (Mayer, 2001, p. 54).
Figure 3 illustrates the theory.
Figure 3: Mayer’s Cognitive Theory of Multimedia Learning
TEN APPLICATION PRINCIPLES OF CLT FOR THE INSTRUCTIONAL DESIGNER The CLT clearly suggests that attention needs to be paid to the effects of learning materials and instruction on cognitive processes. When designing content and activities, instructors need to consider the mental load the learning material poses (intrinsic load), the working memory resources needed in learning material or performing the learning task (germane load) and cognitive processing required for activities not related to learning (extraneous load). Thus, using computer environments as a text repository with little or no related learning tasks may also thwart learning. Based on recent advances of the CLT, the following 10 application principles are suggested. See Figure 4.
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10 1
Goal-free effect
9
Worked example effect
Guidance fading effect
2 8
Completion effect Expertise reversal effect
10 effects of Cognitive Load Theory
Isolated Interacting elements effect
Split-attention effect
3
7 Imagination effect
6
Modality effect Redundancy effect
4 5 Figure 4: Ten Effects of the Cognitive Load Theory
Application Principle 1: the worked example effect Rationale: The working memory has a limited capacity that becomes inefficient when it has to retain even a few items. If limited working memory resources can be used to study worked examples and build new knowledge from them, some of the labour-intensive efforts could be bypassed. Worked examples are more efficient for learning new tasks because they reduce the load in the working memory, thereby allowing the learner to learn the steps in problem solving. Application Principle 2: the completion effect Rationale: Rather than presenting learners with full worked examples, partially completed examples can be used with learners required to complete the missing moves. This procedure partially uses someone else’s knowledge as a central executive to reduce the random generation of moves and is as effective as using full worked examples (Pass 1992; Pass and Van Morrienboer 1994; Van Morrienboar 1990). Application Principle 3: the split attention effect Rationale: Many instructional materials require both a pictorial component and a textual component of information. Conventionally, a graphic representation has been given together with the associated text above, below, or at the side. Such instructional presentations introduce a split attention effect where the student needs to attend to both the graphic representation and the text. Neither the graphic representation, nor the text, alone, provides sufficient information to enable understanding. The instructional material can only be understood after the student has mentally integrated the multiple sources of information. The portion of the working memory that needs to be used in integrating the graphic representation and text is unavailable for the learning process. Consequently, learning is ineffective. To overcome this, the presentation may be restructured to improve learning by physically integrating the solution into the graphic representation to produce a single source of instructional information. This eliminates the need to split attention between the graphic and the text. 111
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Application Principle 4 : the modality effect Rationale: Based on the cognitive load theory and research evidence, it is recommended that when designing e-learning materials, words should be presented auditorily rather than in a printed form whenever the graphic representation or animation is the focus of the words and both are presented simultaneously. The rationale for this recommendation is that learners may experience an overload of the visual/pictorial words that refer to them. If their eyes must attend to the printed words, they cannot fully attend to the animation or graphics. Since being able to attend to relevant words and pictures is a crucial first step in learning, e-learning courses should be designed to minimise the changes of overloading the learners’ visual/pictorial channel. Application Principle 5: the redundancy effect Rationale: The redundancy effect postulates that if one source is unnecessary, then removing one is a better choice or else it is redundant and may result in inefficient use of the working memory. For example, research has indicated that a diagram alone is better than a diagram with text that repeats the information in the diagram. Redundant visual and auditory texts have been found to be less effective than auditory alone (Craig, Gholson, & Driscoll, 2002; Mayer, Heiser, & Lonn, 2001). Application Principle 6: the imagination effect Rationale : Another recently studied instructional effect that benefits more experienced learners is the imagination effect. This occurs when learners who are asked to imagine the content of instruction are found to learn more than learners simply asked to study the material. Imagining is useful for more knowledgeable students who possess appropriate pre-existing schemas, compared to worked examples, while the opposite occurs for less knowledgeable students (expertise reversal effect). It is closely associated with constructing and running mental representations in the working memory which relies on having schemas to support this process. Otherwise, all relevant elements must be processed as individual elements, thus increasing the cognitive load. Imagining may also increase the degree of automation of associated schemas, thereby improving performance. Therefore it is a recommended technique for more experienced learners. Application Principle 7: the isolated interacting elements effect Rationale: For some complex instructional materials, there are occasions in which many interacting elements must be processed simultaneously in the working memory before they can be understood. However, if the nature of the materials is such that the number of interacting elements exceeds the number that can be processed by the working memory, learning with understanding cannot take place. Recent research has found that to address this problem, some of the elements must be processed in an isolated fashion in the working memory, then combined and stored as higher level elements in the long-term memory, before being combined with further elements. By successively reiterating this process, full understanding can eventually occur. Pollock, Chandler and Sweller (1994) found that by presenting such higher element interactivity materials to learners in isolated form rather in their full interacting mode, followed subsequently by the fully interacting mode, learning is enhanced and facilitated. Application Principle 8 : the expertise reversal effect Rationale : A very recent contribution to the understanding of learner experience is the notion of expertise reversal effect, where the positive effects of instructional guidance for novices become a negative effect for experienced learners (Kalyuga et al., 2003). Instructional guidance becomes a burden on the cognitive load when an increased extraneous load is placed on increasingly experienced learners who already have the understanding of the material being presented. Furthermore, an elimination effect occurs when a method is observed to benefit novice learners, but is less effective for more experienced learners – full reversal does not occur. A guidance fading 112
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effect suggests providing a direct instructional application that coincides with the expertise reversal effect, specifically reducing guidance with increased expertise. Application Principle 9 : the guidance fading effect Rationale: A guidance fading effect suggests providing a direct instructional application that coincides with the expertise reversal effect; specifically reducing guidance with increased expertise. Rather than eliminating an instruction-based central executive when a knowledge-based executive becomes available, it may be more effective to slowly fade the instruction-based central executive as the knowledge-based executive develops. It assumes that as levels of expertise increase, the full worked examples associated with the worked example effect can decrease, to be replaced by the practical worked examples associated with the completion effect. These completion problems, in turn, can be replaced by full problems once sufficient knowledge has been accumulated. Application Principle 10 : the goal-free effect Rationale: Means-ends analysis operates on the principle of reducing differences between the stated goal stated and the given problem. Consequently, means-ends analysis may be rendered inoperable by redefining the problem goal so that no obvious goal exists (for example, "find what you can"). This is the principle behind the generation of goal-free problems. If problems are "goal free" then a problem solver has little option but to focus on the information provided (the given data) and to use it wherever possible. This automatically induces a forward working solution path similar to that generated by expert problem solvers. Such forward working solutions impose very low levels of cognitive loads and facilitate learning. DESIGN GUIDELINES BASED ON THE CLT FOR E-LEARNING Taken together, we can make two generalisation statements about the best use of media elements to present content and learning methods in e-learning:
In situations that support audio materials, the most effective learning will result from the concise informal narration of relevant graphics. In situations that rely on visual elements only, for example, text and simple graphics, the most effective learning will result from the concise informal textual explanation of relevant graphics in which the text and graphic are integrated on the screen.
Clark and Mayer (2003) have provided several useful guidelines, which are research-based indicators based on the CLT for e-learning: Apply the research and psychology behind the core principles of the cognitive load theory: the extraneous, intrinsic, and germane types of the cognitive load. Eliminate common sources of the extraneous cognitive load through the best use of graphics, text and audio materials. Impose upon the cognitive load gradually with faded worked examples. Manage the intrinsic cognitive load by weeding and “chunking”.
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Tables 1 to Table 4 below summarise these useful guidelines. Table 1: Media Elements Guidelines for All Types of e-Learning based on the CLT If using the visual mode only: Application Guidelines 1. Use relevant graphics and text to communicate content 2. Integrate the text into the graphics on the screen 3. Avoid covering or separating information that must be integrated for learning. 4. Avoid irrelevant graphics, stories and a lengthy text. 5. Write in a conversational style using the first and second person. 6. Use virtual coaches (pedagogical agents) to deliver the nstructional content If using audio and visual modes: 7. Use relevant graphics explained by audio narration to communicate content. 8. Maintain information the learner needs time to process in the text on the screen, for example, directions to tasks and/or new technology. 9. Avoid covering or separating information that must be integrated for learning. 10. Do not present words as both on-screen text and narration when there are graphics on the screen 11. Avoid irrelevant videos, animations, music, stories and lengthy narrations 12. Script audio materials in a conversational style using the first and second person. 13. Use virtual coaches to present content such as examples and hints via audio materials.
Application Principle Multimedia Principle Contiguity Principle Spatial Contiguity Principle Coherence Principle Personalisation Principle
Multimedia Principle Exception to Modality Principle. Continuity Principle Redundancy Principle Coherence Principle Personalisation Principle Personalisation Principle
Table 2: Guidelines for e-Learning with Performance Goal Outcomes based on CLT Besides all of the above guidelines: Application Guidelines 14. Provide job-relevant practice questions interspersed throughout the lessons. 15. For more critical skills and knowledge, include more practice questions. 16. Design space for feedback to be visible close to practice answers. 17. Provide training in self-questioning when learning from receptive e-lessons. 18. Provide worked examples using realistic job tools and situations in the form of demonstrations for 114
Application Principle Encoding Specificity Principle Practice Principle Contiguity Principle Practice Principle Encoding Specificity Principle
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procedural skills 19. Provide several diverse worked examples for far transfer skills. 20. Provide training in effective ways to study worked examples.
Varied Context for Far Transfer Principle Practice Principle
Table 3: Guidelines for Navigational Options – Learner Control Principles based on CLT Allow learners choices over topics and instructional methods, such as practice, when: 21. Job-relevant practice questions are interspersed throughout the lessons. 22. Courses are designed primarily to be informational rather than skill-building. 23. Courses are advanced rather than introductory. 24. The default option leads to important instructional methods such as practice. Limit learner choices over topics and instructional options when: 25. Learners are novice to the content; skill outcomes are important and learners lack good self-regulatory skills Use advisement diagnostic testing strategies when: 26. Learners lack good self-regulation skills and the instructional outcomes are important. 27. Learners are heterogeneous in terms of background and needs.
Table 4: Guidelines for Training Problem-Solving Skills based on the CLT 28. Use real job tools to teach work-specific problemsolving processes . 29. Provide worked examples of experts’ problemsolving actions and thoughts. 30. Assign learners to write out the problem-solving plans. 31. Provide learners with a map of their problem-solving steps to compare with an expert map. 32. Base lessons on analysis of actions and thoughts of expert practitioners.
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Encoding Specificity Principle Worked Examples Principle Practice Principle Feedback Principle Encoding Specificity Principle
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CONCLUSION The general implications of this paper are two-fold. First, recent research highlights the need for instructional designers to consider the cognitive processes associated with learning. Learners have a limited working memory capacity (cognitive load) and instructional materials should be tailored to maximise the focus on instructional activities (germane load), while mindful of the mental effort necessary for working through the instructional material (intrinsic load) and minimising learners’ attention to activities and materials not directly related to learning (extraneous load). Secondly, the extent to which the various types of cognitive load come into play with selected instructional materials, is dependent upon learner characteristics such as learner experience (or expertise) in a given domain. With these two considerations in mind, instructional designers can then select specific instructional guidance and content components which best promote learning for their students. Future research must identify the real-life conditions under which particular principles do and do not work. REFERENCES Abdul Hadi bin Mat Dawi. (2005). The effects of 3D animations on the learning of orthographic drawing amongst secondary school students. (Unpublished doctoral thesis). University of Science Malaysia. Ahmad Jihadi Abu Samah. (2005). The effects of two modes of multimedia presentations on achievement of accuracy in pronunciations of words of Arabic origin in the Malay language. (Unpublished master thesis). University of Science Malaysia. Baddeley, A. & Hitch, G. (1974). Working memory. In G. A. Bower (ed.) Recent Advances in Learning and Motivation (Vol 8, pp. 47-90). New York: Academic Press. Baddeley, A.D. (1992). Working memory. Science, 255, 556-559. Baddeley, A.D. (1999). Human Memory. Boston: Allen and Bacon. Baddeley, A.D. (2000). Working memory: the interface between memory and cognition. In M. Gazzaniga (ed..) Cognitive Neuroscience: A Reader. Oxford, UK: Blackwell Publishers Ltd. pp 292 304. Chandler, P., & Sweller, J. (1996). Cognitive load while learning to use a computer program. Applied Cognitive Psychology, 10, 151-170. Chen, C. J. (2005). The design, development and evaluation of a virtual reality (VR)-based learning environment: its efficacy in novice car driver instruction. (Unpublished doctoral thesis). University of Science Malaysia. Clark, J.M., & Paivio, A. (1991). Dual coding theory and education. Educational Psychology Review, 53(2), 445-459. Craig, S. D., Gholson, B., & Driscoll, D. M. (2002). Animated pedagogical agents in multimedia educational environments: effects of agent properties, picture features, and redundancy. Journal of Educational Psychology, 94(2), 428-434. Ericsson, K. A. & Kintsch, W. (1995).. Long-term working memory. Psychological Review, 102, 211-245. 116
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Izmi Ismail. (2003). Effects of animated 3D graphics on achievement of students with different cognitive styles and spatial abilities in the learning of earth as a sphere. (Unpublished master thesis). University of Science Malaysia. Kalyuga, S., Ayres, P., Chandler, P., & Sweller, J. (2003). The expertise reversal effect. Educational Psychologist, 38(1), 23-31. Mayer, R. E. (2001). Multimedia Learning. Cambridge, UK: Cambridge University Press. Mayer, R. E., Heiser, J. & Lonn, S. (2001). Cognitive constraints on multimedia learning: when presenting more material results in less understanding. Journal of Educational Psychology, 93(1), 187-198. Miller, G.A. (1956). The magical number seven, plus or minus two: some limits on our capacity for processing information. Psychological Review, 63, 81-97. Norizan Isa (2002). The effect of computer-based multimedia modules with different cognitive loads on achievement of concrete concepts in biology. (Unpublished doctoral thesis). University of Science Malaysia. Paivio, A. (1986). Mental Representations: A Dual-coding Approach. New York: Oxford University Press. Pass, F. & Van Morriℑboer, J.J.G. (1994). Variability of worked examples and transfer of geometrical problem solving skills: a cognitive-load approach. Journal of Educational Psychology 86:122 133. Pass, F. (1992). Training strategies for attaining transfer of problem-solving skill in statistics: a cognitive-load approach. Journal of Educational Psychology 84: 429-434. Peterson, L. & Peterson, M. (1959). Short-term retention of individual verbal items. Journal of Experimental Psychology, 58, 193-198. Pollock, E., Chandler, P. & Sweller, J. (2002). Assimilating complex information. Learning and Instruction 12: 61 – 86. Ruth, C. C & Mayer, R. E. (2003). E-Learning and the Science of Instruction: Proven Guidelines for Consumers and Designers of Multimedia Learning. John Wiley & Sons. Sweller, J. (1988). Cognitive load during problem solving: effects on learning. Cognitive Science, 12, 257-285. Sweller, J. (1994). Cognitive load theory, learning difficulty and instructional design. Learning and Instruction, 4, 295-312. Sweller, J. (1999). Instruction Design in Technical Areas. Camber well, Australia: ACER. Sweller,J., Van Morriℑboer, J.J.G. & Pass, F. (1988). Cognitive architecture and instructional design, Educational Psychology Review 10: 251 – 295. Van Morriℑboer, J.J.G. (1990). Strategies for programming instruction in high school: program completion vs. program generation. Journal of Educational Computing Research 6:265 – 287. 117