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1 Cognitive Information Processing: The Computer as Metaphor Dr. Eva Mary Bures EDU301 Educational Psychology FALL 2010 The cognitive information processing perspective focuses on the learner as a processor of information, analogous to a computer. The overall view is that the learners’ information processing system intervenes between the environment and human behaviour. Most models of information processing are based on a multistore, multistage theory of memory. The chapter describes the basic components of memory from this perspective — sensory memory, short-term memory and long-term memory — as well as the processes hypothesized to help transfer information from each stage to the next. Others were interested in the study of cognition (i.e. Vygotsky, Gestalt psychologists). What distinguishes cognitive information processing is that it relies on the computer as a metaphor. After World War Two, the computer provided an organizing powerful metaphor for developing models of human memory, perception and learning. Stimuli became inputs, and behavior became outputs, with the information processing system of the learner coming in-between. Important orienting questions: What do these models address or explain that behavioristic models do not? What is learning from this perspective as compared to from the behavioristic perspective? Sub-questions: What kind of epistemological assumptions do you see in this approach? Is there a conflict between cognitive information processing approaches and behavioristic approaches or is there a potential complementariness as Driscoll suggests? The following notes sketch out the main concepts covered in the reading, and organize the relevant research. These notes were taken with two main questions in mind: (1) For each main component of memory, what research evidence contributes to our understanding? What about for associated processes such as encoding? (2) What are the instructional implications? 2 Overview of Memory components Most models include three components with processes assumed to help information transfer from one to another. 1st stage Sensory memory holds information in memory briefly – just long enough to be processed 2nd stage Working/short-term memory further processing for long-term storage or response limited time and limited amount of information 3rd stage Long-term memory transferred from short term unlimited Sensory Memory Processes: Attention, Pattern Recognition, Selectivity, Automaticity Sensory Memory & processes Sensory memory Attention Pattern Recognition Some Relevant Research Sperling (1960) partial report technique -- participants can report 3 or 4 of 12 letters in an array of 3 rows; can report 3 or 4 of 4 letters if asked to report on one row only -- sensory memory is temporally, not visually, limited; decays rapidly after 1/4 of a second Darwin, Turvey & Crowden (1972) replicated Sperling (1960) with auditory system; auditory decayed after 4 seconds Broadbent (1957) -- attention seen as a bottleneck or filter Treisman (1960) demonstrated that attention serves to tune out stimulation, but not to filter it i.e. you aren’t listening to another conversation, but if you hear your own name you will notice Grabe (1986), Kaheman (1973) demonstrated that attention is a resource with limited capacity which must be allocated and shared amongst competing goals; selectivity helps focus attention; automaticity helps reduce need for attention Environmental stimuli recognized as ‘exemplars.’ Process explained by several models: template matching (fails as explanation – would need templates for all different A’s); prototype model; feature analysis. None of these explain why deteriorated ‘A’ is seen as an ‘A’ on a gravestone: effects of context. Gestalt principles of organization suggest we go ‘beyond the information’ given to construct meaningful interpretation – principles of closure, and 3 proximity and similarity effects Selectivity Automaticity Past experience or prior learning can interfere in appropriate recognition. The Stroop effect: an individual is shown several color words (i.e. blue) that are printed in different colors and is then asked to name the colors; confusion results, and participants tend to name the actual words Sternberg & Davidson (1983): in problem-solving, students often try to solve problems using familiar solutions; providing them with practice in a variety of contexts can help reduce this effect. Good and Brophy (1984) suggest that teachers use standard signals to influence attention (i.e. “let’s begin!”) Grabe (1986) suggests that learners be taught to be less impulsive in responding to a task and that they should be trained in a strategy for focusing attention. Shiffrin & Schneider (1977) showed that many procedures are partially automaticized and partially controlled such as in driving LaBerge & Samuels (1974) found that decoding words becomes automatic in processing text Anderson (1982) found that readers allocate greater attention to important elements in a text 4 Working Memory Processes: rehearsal and encoding Working Memory & associated processes Working Memory Rehearsal Encoding Some Relevant Research George Miller (1956): demonstrated that subjects could remember 7 +/- numbers. Memory span does appear to cover this number of chunks (hence, chunking strategies). Brown (1958) and Peterson and Peterson (1959) tried to estimate the duration of working memory. They presented subjects with sets of 3 letters that they needed to recall. If rehearsal is prevented, information is lost from working memory in about 15 to 30 seconds. Rehearsal and coding help address this loss. Primacy effect: if subjects are given sets of items to remember at a slow rate, subjects are able to remember the most recent items (recency effect) as well as the first few items (primacy effect). Rehearsal does not help transfer information into long-term memory. Elaborative rehearsal can. Encoding means connecting new information to familiar concepts and ideas. This makes new information more memorable. Bousefield (1953) found that people related information into categories to help learn them or remember them. Tulving (1962) found that learners impose their own organization onto even unrelated information. Many cognitive strategies to help learners encode information have been studied. 5 Long Term Memory: Processes: retrieval Long term memory Representation of imagery Retrieval Recall Recognition Retrieval cues Forgetting Tulving (1972) distinguishes between episodic versus semantic memory, where episodic refers to memory of specific events that is entirely dependent on the context and semantic memory refers to information that can be recalled independently of how it was learned. Since Tulving, educators focus on semantic memory. Several models of semantic long-term memory have been developed i.e. network models, feature comparison models, propositional models, parallel distributed processing (PDP) models Shepard et al (1978): when subjects have to find a match for a rotated three-dimensional object, the time it takes to find the match is directly related to the spatial rotation needed Paivio (1971) posits a dual-code theory, one system for verbal information, and another for non-verbal. This explains why subjects can more easily remember concrete words such as sailboats -- they draw on both verbal and non-verbal representations Kosslyn et al (1973) found that the time subjects take to estimate the distance between two places on a map reflects the linear distance between the places To recall information, no cues or hints are provided to learners. Subjects do not tend to remember much in these conditions. Cued recall tasks involve cues that help learners remember the important relevant information. To judge reading comprehension, Royer et al (1984) present learners with old-new recognition tasks. They need to recognize an original sentence from the passage and a paraphrase of the original sentence, and need to classify as new both a sentence that is almost exactly the same as the original sentence with altered meaning and a distractor sentence which is unrelated to the original sentence. Encoding specificity principle (i.e. Thomson & Tulving, 1970): learners recall best when retrieval cues are the same cues they used to facilitate encoding. Common explanations for forgetting: failure to encode, failure to retrieve and interference. 6 Models of LTM • For each model of memory representation (LTM), what phenomenon does it explain? What phenomenon does it not explain? What are the basic units? Model of LTM Network models Knowledge Unit nodes or concepts Feature Comparison Models nodes or concepts Propositional Models proposition (subject and predicate) Parallel Distributed Processing (PDP) subsymbolic units and connections Relations amongst units relations between nodes are learned; take the form of interconnected hierarchies Evidence: what does it explain? individual differences among learners speed at which subjects will recognize truth of statements i.e. a blue heron has long legs versus a blue heron is an animal (Collins & Quillian, 1969) fails to explain typicality effects i.e. subjects fail to recognize a penguin as a bird as quickly as they do a canary stored in sets of Smith, Shoben & Rips (1974) defining explains typicality effects: some features; members are better examples of concepts are concepts than are others. Defining associated with features are shared by all members, one another if whereas characteristic features may enough features belong only to the more typical overlap members of a set. helps deal with fuzzy concepts - fails to account for semantic flexibility Kintsh (1974) found that subjects take longer to read sentences containing many rather than few propositions, even with the same number of words used. In recall, sentence structure tends to be lost, but propositions are remembered. Anderson (1976) has developed ACT, a network model with propositional structure. processing is account for incremental nature of distributed learning (Estes, 1988); integrate role across a network of goals; may help explain cognitive of units & development by clarifying what is connections; hard-wired (McClelland, 1988). weights are Not clear that PDP models actually associated with represent the neural processes in the the connections. brain (Estes, 1988). 7 Implications on instruction: Three major recommendations listed in the textbook: Provide organized instruction Make evident to learners the structure and relations of material such as through concept maps or other graphic representations. Arrange extensive and variable practice Variable practice allows learner to generalize the concept, principle, or skill beyond the context it was learned in (transfer of learning). And reduce effect of past experience interfering (for example, in problem solving, trying a technique for a familiar problem in the wrong situation) Enhance learners’ self-control of information processing Assist them in learning, selecting and using appropriate learning strategies such as summarizing and questioning. Generally, learning strategies should be done within a specific domain; students need to know how and why various selfregulatory strategies work. Three variables influence metacognitive ability: person variables (i.e. older people are more conscious of strategies and using them); task variables (i.e. learner tends to use general learning strategies with new information and then to use more content-specific ones as their expertise increases); and strategy variables (some strategies such as breaking down a complex task are easily acquired; others such as taking notes take extensive practice). Other key implications: Sensory Memory techniques to help focus attention (limited resource) Good and Brophy (1984) suggest that teachers use standard signals to influence attention (i.e. “let’s begin!”) Grabe (1986) suggests that learners be taught to be less impulsive in responding to a task and that they should be trained in a strategy for focusing attention. Learners’ goals and the features of the text influence their allocation of attention to different elements (Anderson, 1982). Stimulus features, idea unit structure (placement of ideas in a text), voice inflection or gestures, novelty, questions inserted into the text and assigning instructional objectives can be used to focus students’ attention on key aspects of the instructional materials. Automaticity: LaBerge & Samuels (1974) suggest that learners should be able to decode words automatically in order to read for meaning. Reading aloud and extended word identification practice are two strategies to increase automaticity. Other implications focused on pattern recognition: 8 Drawing on feature analysis, Tennyson & Cocchiarella (1986) propose model for teaching concepts: present a prototypic concept followed by examples that vary systematically from it. Past experience has an influence on pattern recognition. Knowledge can help; it scan also interfere. Solving problems can require seeing things a different way. Practice on many different kinds of problems may help (role of context becomes a variable they see is important in solving problems). Short-term Memory Enhancing Rehearsal To improve rehearsal, recognize limitations of short-term memory. Use the concept of chunking: don't present 49 separate items, make them 7 groups of 7. Use elaboration and multiple contexts. Enhancing Encoding Having and activating relevant prior knowledge – very very important. Outlines, hierarchies and concept trees help people encode meaningfully. Mneumonics (although some people are skeptical that this leads to deep processing) and mediation. Imagery. Elaborative encoding better than mere repetition. But learners do develop own idiosyncratic encoding strategies, which it may be best to encourage (i.e. Pressley & Levin, 1983). i.e. invent own mnemonics; self-questioning. Match encoding strategies with the material to be learned. To encourage deeper processing, avoid mnemonic techniques. Provide opportunities for both verbal and imaginal encoding. Concrete words are remembered better than abstract ones. Long-term memory Enhancing retrieval Cues can enhance students’ recall: implication is cue tasks i.e. add qualifiers to essay questions. Note-taking, elaboration Decrease proactive interference especially with older adults: signal main ideas; visual displays organizing information in concepts and showing structure. Encoding specificity principle (i.e. Thomson & Tulving, 1970): learners recall best when retrieval cues are the same cues they used to facilitate encoding: place (Bilodeau & Schlossberg, 1951); drugs (Goodwin et al, 1969); emotions (Brown, 1981). Representation in multiple perspectives and in multiple contexts. 9 Other important implications will be discussed in chapter ten: For example: Gagne’s nine events of instruction: gaining attention, informing learners of objectives, stimulating recall of prior learning, presenting the stimulus, providing learning guidance, eliciting performance, providing feedback, assessing performance, enhancing retention and transfer. Side-note of Interest: Representation of Images One issue covered briefly in the textbook is the representation of information other than verbal information. Imagery has been discussed since Platonic times. It has special significance to educational technologists of our day. Research suggests that visual and verbal information are not stored the same way. For example, Kosslyn, Ball & Reiser found evidence that visual images preserve spatial information. Shepard & Metzler (1971) * Kosslyn, S.M., Ball, T.M., & Reiser, B.J. (1978). Visual images preserve metric spatial information. Evidence from studies of image scanning. Journal of Experimental Psychology: Human Perception and Performance, 4: 47 - 60. Jolicoeur, P. & Kosslyn, S.M. (1985). Is time to scan images due to demand characteristics? Memory and Cognition 13: 320-332. • tested hypothesis that experimenter expectancy effects operated to increase times in distance subjects perceived. were unable to replicate the effects found by IntonsPeterson (1983). Intons-Peterson, M. J. (1983). Imagery paradigms: How vulnerable are they to experimenters’ expectations? Journal of Experimental Psychology: Human Perception and Performance 9: 394-412. for applications to educational technology: see Paivio dual-code theory applied to inclusion of multiple representations in instructional materials and related research. • What evidence exists concerning the role of images in memory? • What are the implications of different type of mental representations for educational technologists? Précis of Mental Rotation of Three-Dimensional Objects Shepard & Metzler (1971). The experiment investigated the amount of time human subjects took to identify whether 2-dimensional depictions of 3-dimensional geometric shapes were different. Sixteen hundred pairs of geometric objects were presented to 8 adult participants. Of these pairs, 800 were different, 400 were the same and differed by a multiple of a 20 rotation in the two dimensional picture plane (‘picture-plane pairs’), and 400 were the same and differed by a multiple of a 20 rotation about a vertical axis (‘depth pairs’). Participants were presented with a total of 800 unique pairs: each pair was shown twice. The same pairs consisted of 20 depth and 20 picture plane pairs at each 20 10 interval from 0 to 180 (10 different angles). In both the case of the picture-plane and the depth pairs, the mean reaction times of subjects was linearly related to the angle of rotation. Of course individual reaction times varied. Nonetheless, the linearity of the relationships were evident. Each individual’s scores were plotted separately for each type of rotation. In all 16 cases, all tests against deviations from linearity were significant (p<0.001) and no quadratic relationships were found (p>0.05). The reaction times suggested that subjects took roughly 60 per second for both 3-dimensional and 2-dimensional rotations to ‘mentally rotate’ the objects.