What are exemplars and how are they used? What will be an ...

[anshika]

What are exemplars and how are they used?
 
  What will be an ideal response?

Question 2

Describe Newell and Simon's (1972) production system and production rules.
 
  What will be an ideal response?

[Swizqar]

Answer to Question 1

Some psychologists suggest that instead of using a single abstract prototype for categorizing a concept, we use multiple, specific exemplars. Exemplars are typical representatives of a category. For example, in considering birds, we might think of the prototypical songbird, which is small, flies, builds nests, sings, and so on. We also might think of exemplars for birds of prey, for large flightless birds, for medium-size waterfowl, and so on. So although a prototype is an averaged representation of all the objects in a category, an exemplar is not necessarily averaged over all objects. Instead, there can be exemplars for different subtypes of objects within a category, like birds of prey and flightless birds. A penguin or ostrich can be a good exemplar within the category of birds (they exemplify the group of flightless birds), but they are not prototypical exemplars because those birds cannot fly. Some investigators use this approach to explain how categories are both formed and used in speeded classification situations. In particular, categories are set up by creating a rule and then by storing examples as exemplars. Objects are then compared to the exemplars to decide whether or not they belong in the category the exemplars represent.

Answer to Question 2

One way in which computers can represent and organize procedural knowledge is in the form of sets of rules governing a production, which includes the generation and output of a procedure. Computer simulations of productions follow production rules (ifthen rules), including an if clause and a then clause. People may use this same form of organizing knowledge or something close to it.

For example, suppose your car is veering toward the left side of the road. Then you should steer toward the right side of the road if you wish to avoid hitting the curb. The if clause includes a set of conditions that must be met to implement the then clause. The then clause is an action or a series of actions that are a response to the if clause.

For a given ifthen rule, each condition may contain one or more variables. For each of these conditions, there may be one or more possibilities. For example, if you want to go somewhere by car, and if you know how to drive a car, and if you are licensed and insured to drive, and if you have a car available to you, and if you do not have other constraints (e.g., no keys, no gas, broken engine, dead battery), then you may execute the actions for driving a car somewhere. When the rules are described precisely and all the relevant conditions and actions are noted, a huge number of rules are required to perform even a simple task. These rules are organized into a structure of routines (instructions regarding procedures for implementing a task) and subroutines (instructions for implementing a subtask within a larger task governed by a routine). Many of these routines and subroutines are iterative, meaning that they are repeated many times during the performance of a task.

If you want to complete a particular task or use a skill, you use a production system that includes the entire set of rules (productions) for executing the task or using the skill