Presentation on theme: "Schema Theory. Evaluate schema theory with reference to research studies Evaluate schema theory with reference to research studies What is schema theory."— Presentation transcript:
Evaluate schema theory with reference to research studies Evaluate schema theory with reference to research studies What is schema theory ? What is schema theory ? Learning Outcomes (from the IB Syllabus)
Schema Theory What is a Schema? “A mental model or representation built up through experience about a person, an object, a situation, or an event.” (Head, 1920) “Organised structures of knowledge and expectations of some aspect of the world.” (Bartlett, 1932)
Schema of an “egg”
What is a schema ? Schema theory seeks to explain our interpretation of the world from a psychological perspective, which stems from cognitive science. Schemas (or schemata) are cognitive structures (mental templates or frames) that represent a person's knowledge about objects, people or situations. Schemas (or schemata) are cognitive structures (mental templates or frames) that represent a person's knowledge about objects, people or situations. Schemas are derived from prior experience and knowledge. They simplify reality, setting up expectations about what is probable in relation to particular social and textual contexts.
What is a schema ? Schemas are used to organise our knowledge, to assist recall, to guide our behaviour, to predict likely happenings and to help us to make sense of current experiences. Schema theory predicts that we interpret our experiences by using relevant social and textual schemas. Bartlett (1932) described how schemata influence memory in his research with 'Story of the ghosts'. A schema can be seen as a kind of framework with 'slots' for 'variables', some of them filled-in and others empty.
What is a schema ? Schema theory predicts that we interpret our experiences The slots are either filled in already with compulsory values (e.g. that a dog is an animal) or 'default values' (e.g. that a dog has four legs) or are empty (optional variables) until ' instantiated' with values from the current situation (e.g. that the dog's colour is black). When what seems like the most appropriate schema is activated, inferences are generated to fill in any necessary but inexplicit details with assumed values from the schema.
If no relevant schema is retrieved from long-term memory a new schema is created. Explicit events and inferences, as well as new schemas, are stored in long-tern memory. Schema-driven processing is a top-down perceptual process that guides a selective search for data relevant to the expectations set up by the schema. Schema-driven processing is a top-down perceptual process that guides a selective search for data relevant to the expectations set up by the schema. Schema-driven processing interacts with bottom- up data-driven processes (which may lead to the activation, modification or generation of a schema). Schema-driven processing interacts with bottom- up data-driven processes (which may lead to the activation, modification or generation of a schema).
Schema theory is consistent with the notion of both perception and recall as constructive and selective cognitive processes. Schemas are culturally specific: schemas for common routines vary socio- culturally- even within a single country.
War of the Ghosts (1932) This was an unusual story for people from a Western culture to understand because it contained unfamiliar supernatural concepts and an odd, causal structure. After an interval participants were asked to recall as much of the story as possible. After an interval participants were asked to recall as much of the story as possible.
methodology Serial reproduction – participant reads and recalls the story, second person reads and recalls the second reproduction…….and so on Repeated reproduction – partipants reads the story and repeats it over various recall intervals
The War of the Ghosts One night two young men from Egulac went down to the river to hunt seals, and while they were it became foggy and calm. Then they heard war cries and they thought; 'Maybe this is a war-party.' They escaped to the shore, and hid behind a log. Now canoes came up, and they heard the noise of paddles and saw one canoe coming up to them. There were five men in the canoe and they said; 'What do you think? We wish to take you along. We are going up the river to make war on the people.' One of the young men said; 'I have no arrows.' 'Arrows are in the canoe,' they said. 'I will not go along. I might be killed. My relatives do not know where I have gone. But you,' he said, turning to the other, 'May go with them.' So one of the young men went, but the other returned home. And the warriors went on up the river to a town on the other side of Kalama. The people came down to the water and began to fight, and many were killed. But presently, one of the young men heard one of the warriors say; 'Quick let us go home. That Indian has been hit.' Now he thought; 'Oh, they are ghosts.' He did not feel sick, but he had been shot. So the canoes went back to Egulac, and the young man went back to his house and made a fire. And he told everybody and said; 'Behold, I accompanied the ghosts, and we went to fight. Many of our fellows were killed and many of those that attacked us were killed. They said I was hit, but I did not feel sick.' He told it all, and then he became quiet. When the sun rose, he fell down. Something black came out of his mouth. His face became contorted. The people jumped up and cried. He was dead.
War of the Ghosts (1932) Bartlett found that their accounts were distorted in several ways that, generally, made them more consistent with a Western world – view. Specifically he found the following;
Findings/Results Some things in the story were changed by the participants, especially parts of the story that were difficult for the participant to comprehend (i.e. ghosts and the Indian's death). Ghosts coming out of the mouth of the unconscious Indian was commonly written. The excuse for not fighting "I have run out of arrows" was avoided and instead put down to "worried relatives", because it was more familiar to the participant. Every participant rationalized the.story to some degree
Findings/Results Some added material to the story to bring it into closer agreement with their prior knowledge and beliefs (for example he had a fever before he died). Some added material to the story to bring it into closer agreement with their prior knowledge and beliefs (for example he had a fever before he died). There was a tendency for males to forget the 'no arrows' excuse for joining the war. This was because many men were going off to war and relatives would miss him were in the forefront of the participants minds.
Findings/Results Bartlett found that participants tended to alter their memories in order to make the story more coherent. This often involved them down playing the things they did not understand, such as the supernatural elements: The participants were not reading back a copy of the story but reconstructing it from the main details held in their memory. Bartlett found that participants tended to alter their memories in order to make the story more coherent. This often involved them down playing the things they did not understand, such as the supernatural elements: The participants were not reading back a copy of the story but reconstructing it from the main details held in their memory.
Evaluation of Bartlett’s study The ecological validity of the War of the Ghosts lab study has been questioned. Whilst Bartlett rejected the artificiality of traditional stimulus such as nonsense syllables ( Ebbinghaus) and word lists to test memory, his use of a native American folk tale was " about as similar to normal prose as nonsense syllables are to words
Evaluation of Bartlett’s study Wynn & Logie (1998) did a similar study with students using " real - life" events experienced during their first week at university at various intervals of time ranging from 2 weeks to six months. They found that the initial accuracy of recall was sustained throughout the time period, suggesting that schema-induced memory distortions may be less common in naturalistic conditions than in the laboratory.
Evaluation of Bartlett’s study Furthermore Bartlett’s study wasn't a very well controlled study. Bartlett did not give very specific instructions to his participants ( Barlett, 1932 " I thought it best, for the purposes of these experiments, to try to influence the subject's procedure as little as possible".) As a result, some distortions observed by Bartlett may have been due to conscious guessing rather than schema-influenced memory Gauld and Stephen ( 1967) found that the instructions stressing the need for accurate recall eliminated almost half the errors usually obtained.
Further support for the influence of schemas on memory at encoding point was reported by Anderson and Pichert ( 1978).
Subjects asked to adopt a particular perspective: Home-buyerBurglar Then read a passage about two boys playing truant from school... 2 nd supporting study schema theory ( Anderson & Pichert, 1978)
Schemata and Memory (Anderson & Pichert, 1978) [Coding: Burglar items (18); Homebuyer items (18)] There are three color TV sets in the house. One is in the large master bedroom (which has a three piece bathroom en suite), one is in the main floor family room, and one is in Tom's bedroom. The house contains four bedrooms in all, plus an office, family room, and three washrooms. In addition to the TV, the family room contains a new stereo outfit, a microcomputer, a VCR, and a rare coin collection. The boys enter the master bedroom. Beside the jewelry case in the closet they find Tom's father's collection of pornographic video tapes. They select their favorite (an encounter between a guy and 12 women in a park in downtown Kitchener) and go to the family room to watch it.
Evaluation of schema theory Anderson & Pichert ( 1978) In a classic experiment, Pichert and Anderson 1 asked participants to read a story in which a house was described. 1 The participants were told to read the story from one of two perspectives, either a potential home buyer or a burglar. After a delay, participants were asked to recall as much as they could about the story.
Items Proportion Recalled During this first recall session, participants recalled significantly more information about the house that was relevant to their perspective (e.g., the potential home buyer might remember defects in the house, burglars might remember information about the entrances and exits) than information that was relevant to the other perspective,
After the first recall session, participants were told to think about the story again, but this time, from the other perspective (potential home buyers were now told to be burglars, and vice versa). Then, without reading the story again, they were told to recall as much as they could about the story again. During this second recall, participants were able to recall information about the house that was relevant to their new perspective, but which they had not recalled before. Items First identity/second identity Change in proportion recalled
This result shows two things: 1.) The information that was irrelevant to their original perspective (schema) was actually learnt ( encoded ) and 2.) This information was not accessible unless a relevant perspective (schema) was activated.
Evaluation of Anderson & Pichert (1978) This experiment was also conducted in a lab, so ecological validity may also be an issue here. However the strength of the experiment was its variable control, which allowed researchers to establish a cause-and-effect relationship how schemas affect memory processes.
Evaluation of Schema theory Strengths: Support for the influence of schemas on cognitive processes is widespread. Bartlett (1932) described how schemata influence memory in his classic study based on a Native American folktale. Helps explain many cognitive processes (perception, memory, reasoning) Helps explain the reconstructive nature of memory – eg eye-witness testimony, stereotyping, gender identity, cultural differences
General comment on schema theory Finally, one of the main problems of the schema theory is that it is often very difficult to define what a schema is. Cohen (1993) points out that "the whole idea of a schema is too vague to be useful' and argues that schema theory provides no explanation of how schemas work. Schemas are untestable Schema processing is not fully understood
General comment on schema theory Nevertheless, there is enough research to suggest schemas do affect memory processes knowledge, both in a positive and negative sense. They do simplify reality, and help us to make sense of current experiences. Schemas are useful concepts in helping us understand how we organize our knowledge.