Chapter 9- Conceptual Knowledge Flashcards
Conceptual knowledge
Knowledge that enables us to recognize objects and events to make inferences about their properties. When we encounter a new item or event, how do we know what it is? How do we distinguish items from each other?
Concepts
Defined in a number of ways- the mental representation of a category or individual, or categories of objects, events, or ideas, or “glue” that holds our mental world together. Concepts are the form in which knowledge exists that lets you recognize objects or understand what’s going on around you. Describing a cat as an animal that meows is describing an aspect of a concept.
Category
Learned organizations or groupings of concepts. Includes all possible examples of a specific concept. The category “cats” includes all of the different types of cats. Mental representations of objects (concepts) provide our rules for how we place things in each category.
Categorization
The process by which things are put into categories. This refers to new things, like an unclassified instance or exemplar. Once we recognize something as being part of a category, we know a lot about it “pointers to knowledge”. For example, recognizing an animal as a cat provides a lot of information about its behavior. Categories allow us to take action to interact with our environment. To begin spreading butter on bread, we need to know all the different things we need to do to accomplish this and all the rules about what bread, butter, and knives are like.
How do categories help us understand behavior?
Certain behaviors make sense once we can place a person in a certain category. For example, a man wearing black and gold face paint might not make sense until you realize he’s heading toward the football stadium. Then, you realize he can be categorized as a Pittsburgh Steelers fan.
Classical/definitional approach to categorization
States that we can decide whether something is a member of a category by determining whether a particular object meets the definition of the category. For example, a square is defined as a shape with 4 equal sides
Why don’t definitions work for categories?
Definitions work for some things, like geometric shapes. However, not all members of a category will have the same features. A chair might be defined as furniture with a back and arms, but not all chairs will meet that definition.
Family resemblance
Wittgenstein- refers to the idea that things in a category resemble one another in different ways. This approach allows for some variation in a category, unlike the dictionary definition. All chairs must resemble the other chairs in the category in some way or share some similar characteristic
Prototype approach to categorization
Membership in a category is determined by comparing the object to a prototype that represents that category.
For the prototype approach, what determines if something is a typical member of a category?
Rosch- stated that the typical prototype is based on the average of members of a category that are commonly experienced. A prototype for bird might look like a combination of birds you typically see, but it doesn’t have to exactly resemble any of them. The ideal category member will serve as a reference point
Typicality
The degree to which a category member resembles the prototype of the category. Differences in typicality are the differences within categories (there are many different types of birds, and some are very different from others). High typicality means that a category member closely resembles the prototype of that category.
Rosch typicality experiment
Participants were given a list of items in different categories, and were asked to rate the extent to which each item represented the category. The low rating for sparrow, for example, showed that participants considered sparrows to be good examples of birds, while penguins were considered bad examples.
How well do good and poor examples of a category compare to other items in the category? (Rosch and Mervis)
Participants were given a list of objects and were asked to list as many attributes or characteristics of the object as they could. Similar objects, such as chair and sofa, were given many of the same characteristics, meaning that the family resemblance was high. With objects like mirror and phone, resemblance was low, even though they both can be classified as furniture. It was concluded that there’s a strong relationship between family resemblance and prototypicality- good examples of the category share many attributes with other members of the category.
Sentence verification technique (Smith)
Participants were presented with statements and asked to answer yes or no depending on if they thought that the statement was true or not. Participants responded faster for objects that are high in prototypicality than for objects that are low in prototypicality.
Typicality effect
The ability to judge highly prototypical objects more rapidly. Typical exemplars also tend to be listed prior to less typical exemplars.
When participants are asked to name objects in a category, which objects tend to be named first?
Prototypical objects are named first. Therefore, a sparrow would be named before a penguin when participants were asked about birds
Priming
Occurs when presentation of one stimulus facilitates the response to another stimulus that usually follows closely in time, if it contains some of the information needed to respond to the stimulus. Prototypical members of a category are more effected by a priming stimulus.
Rosch priming experiment
Participants heard the prime first, which was the name of a color. They then saw a pair of colors side by side and indicated as quickly as possible whether the colors were the same or different. Colors were either the same and good examples of the category, the same and poor examples (light blue, etc) or different. The same judgements for the prototypical colors were faster than same judgements for non prototypical colors. The prime facilitates the participants’ responses to the prototypical stimulus because when they hear the name of a color, they imagine a prototypical example of that color.
How did Rosch’s research provide an advance over the definitional approach?
It provided a lot of experimental evidence that all items within a category are not the same.
Exemplar approach to categorization
Involves determining whether an object is similar to other stored objects. The standard for this approach involves many exemplars, and each known exemplar acts as a reference point. This approach explains the typicality effect by proposing that objects that are more like exemplars are classified faster. A sparrow is similar to many exemplars, so it’s classified faster because there are more reference points for that item
Exemplars
Actual members of a category that a person has encountered in the past. If a person has encountered sparrows, robins, and blue jays in the past, they would be exemplars of the bird category.
Advantages of the exemplar approach
- It can take atypical cases into account by using real examples. Flightless birds are not typical but can be exemplars of this category, rather than getting lost in the “average of a bird” proposed by the prototypical approach
- It can deal more easily with variable categories like games- we only need exemplars of some of the varying examples to recognize them
Are prototypes or exemplars better for recognizing objects?
People might use both approaches. When we initially learn about a category, we might average exemplars into a prototype. Later on, the exemplar information strengthens. We know what cats are (a prototype) but we know our own cat best (an exemplar).
Hierarchical organization
Where general categories are divided into smaller, more specific categories. Some chairs can be categorized as kitchen chairs and others as dining room chairs.
3 levels of categories in hierarchical organization (Rosch)
- Superordinate level- also known as the global level, “furniture”.
- Basic level- “table”
- Subordinate level, or the specific level. Example- “kitchen table”
Rosch basic level
Participants were asked to list features of different levels- for furniture, tables, and kitchen tables. They listed only a few features that were common to all furniture, and more that were common to all tables or all kitchen tables. Rosch proposed that going above the basic level (to furniture) results in a loss of information, and going below it (to kitchen table) does not provide a gain in information. This category is most commonly used in language, when naming things
How do the names of things relate to basic level categories?
When asked to name objects, participants often gave their basic level name. For example, “guitar” rather than electric guitar (specific) to musical instrument (global). When participants were shown a category label and then shown a picture, participants identified the object as being part of the category more quickly if they had been given the basic category label.
How does knowledge affect categorization?
Nonexperts on a category are likely to describe an object as belonging to the basic category. However, experts on a category (plants, birds) are more likely to assign those objects to a specific category. This is because they have learned to pay attention to features that nonexperts aren’t aware of. To categorize objects, the learning and experience of the people categorizing them matters.
Semantic network approach
Proposes that concepts are arranged in networks in the mind.
Collins and Quillian’s semantic network model
The network consists of nodes that are connected by links. Each node represents a category or concept, and related concepts are connected by directional associations (links). Properties are indicated for each concept using arrows. The connected related concepts indicate how each concept is related to each other in the mind- canary and bird, and bird and animal, are connected in the mind.
Hierarchical model
A model that consists of levels arranged so that more specific concepts, like “canary”, are at the bottom, and general concepts are at higher levels. There are directions to these relationships. This describes Collins and Quillian’s semantic network model.
Cognitive economy
Storing properties of an object just once, at a higher level node (in the hierarchical model). This saves space and makes the network more efficient. It does create a problem saying “can fly” at the bird node for example, because not all birds can fly. Exceptions can be added at lower nodes with the unique properties of that node.
