Making Sense of the World - Why Do We Need Concepts?

1. Making Sense of the World -Why Do We Need Concepts? • Too much information to treat each piece individually • Concepts are necessary for effective communication • It is useful to group similar things together • Concepts allow us to go beyond the information given to make inferences and understand what is going on • Guide our attention and interpretation • Concepts allow us to reason about problems we face

2. Going Beyond the Information Given The procedure is actually quite simple. First you arrange things into different groups. Of course, one pile may be sufficient, depending on how much there is to do. If you have to go somewhere else due to lack of facilities, that is the next step; otherwise you are pretty well set. It is important not to overdo things. That is, it is better to do too few things at once than too many. In the short run this may not seem important but complications can easily arise. A mistake can be expensive as well. At first the whole procedure will seem complicated. Soon, however, it will become just another facet of life. It is difficult to foresee any end to the necessity for this task in the immediate future, but then one can never tell. After the procedure is completed one arranges the materials into different groups again. Eventually they will be used once more and the whole cycle will then have to be repeated.

3. 9 N D 6 How Concepts Guide Interpretation

4. Not Drinking Drinking 16 19 Now Try It When You Understand the Concepts

5. What Concepts Are We Thinking About - Activating Concepts • Stimulus features - this seems obvious so it really hasn’t been studied • Salience • Solo Status Studies • McGuire Studies • Priming - • The Donald Study (Srull & Wyer, 1979) • The Devine (1989) Study • Chronic Accessibility • Goals

6. Donald I ran into my old acquaintance Donald the other day, and I decided to go over and visit him, since by coincidence we took our vacations at the same time. Soon after I arrived, a salesman knocked at the door, but Donald refused to let him enter. He also told me that he was refusing to pay his rent until the landlord repaints his apartment. We talked for a while, had lunch, and then went out for a ride. We used my car, since Donald’s car had broken down that morning, and he told the garage mechanic that he would have to go somewhere else if he couldn’t fix his car that same day. We went to the park for about an hour and then stopped at a hardware store. I was sort of preoccupied, but Donald bought some gadget, and then I heard him demand his money back from the sales clerk. I couldn’t find what I was looking for, so we left and walked a few blocks to another store. The Red Cross had set up a stand by the door and asked us to donate blood. Donald lied by saying he had diabetes and therefore could not give blood. . .

7. The Nature of Concepts • Classical View - you can define things with necessary and sufficient categories. • Problems with this view - • Often it is hard to define things (What is a date?) • All members of a category are not equally good members • They vary in typicality • Unclear examples • Probabilistic View - (think of birds) • Fuzzy categories • Family resemblance

8. Probabilistic View - The Evidence • People make reliable typicality ratings • A desk chair and a dining room chair are typical chairs • A recliner and an office chair are less typical • A beanbag chair and a computer chair are atypical • People can make quicker judgements about typical objects • When asked for examples people nominate the typical objects • There is a strong correlation between how typical an object is and the number of features it shares with the category

9. Two Types of Probabilistic Models • Prototype Model • Abstracted list of features that are typical of category members • Think of a used car salesman • Dishonest, slick, can talk your ear off, confident, persuasive, obnoxious, etc. • Exemplar Model • No summary just specific instances are stored in memory • Think of a used car salesman • My brother, Chick the guy I bought my last car from, Bill the nice guy who sold me 3 different cars, etc.

10. So Which Is It? Evidence for Prototype Model • Evidence for the Prototype View - People’s judgments are sometimes made independently of their memories about specific group members • Park & Hastie (1987) • Gave people descriptions of two groups • Gave people examples of people in the groups • Manipulated memory for examples by repeating them • Descriptions mattered more than examples in ratings of the group and generalization from the group to new members

11. Evidence for Exemplar Model • Evidence for the Exemplar View - Priming people with exemplar’s influences people’s judgments • Schwarz & Bless (1992) • Asked some people to name politicians involved in a scandal; others were not asked to name politicians • They then evaluated politicians in general and several specific politicians

12. Schwarz & Bless (1992)

13. Critique of the Probabillistic View • How do we decide what to make similarity judgments on? • What counts as a feature? - any two objects share an infinite number of features and we are more likely to categorize on some features than on others. Think of professors and rocks. • How do we weight the different features that do count? - weighting features differently in different situations can lead to very different similarity judgments. Think of pandas newspapers and koalas. • Classification by similarity alone ignores relations among attributes - think of dogs; while it is true that they bark and it is true that they can protect people, we also know that sometimes they bark to protect people.

14. Concepts as Theory-Based • Support for this point of view • Category membership overrides similarity even in children • Gelman & Markman (1986) Swallows are more similar to Flamingos than Bats • Goal derived categories that have no apparent similarity • Going swimming, painting, jumping rope, eating cookies • Experts categorize things differently • Classification of wood • Combined Concepts • Muscle Car

15. Critique of Theory Based Concepts • Evidence isn’t clear enough to be more than suggestive - Let’s look at some examples • Category membership overrides similarity - what kind of similarity are we taking about, physical similarity yes, but perhaps there are other similarities picked up in these studies • Goal derived categories that have no apparent similarity - Perhaps the dimensions of similarity are just not readily apparent • Experts categorize things differently - Perhaps experts just have different organizations to the prototypes or exemplars • Combined Concepts - Perhaps these are just subtypes of the more general prototype

16. Where Does This Leave Us? • Classical Approach has been discredited and probably only applies in rare situations • The Probabilistic View and the Theory-Based Concept View both have merit but 2 questions remain • Can the two be differentiated? i.e. can either account explain any finding? (This suggests more precision is needed in the theories) • When does each account prove most useful? • Within Probabilistic View- the same two questions exist when comparing prototypes and exemplars

17. Organizations of Categories within a Concept • Levels of concepts and meaning - Rosch proposed three levels • Superordinate Categories • Middle Level or Basic Level Categories • Subordinate Categories • She proposes that at superordinate categories it is difficult to talk about common attributes (hard to describe) • She proposes that at subordinate categories requires too much cognitive energy to make differentiations (hard to differentiate) • Basic categories are easy to describe and easy to differentiate from other objects

18. Table Lamp Chair Kitchen Table Dining Room Table Floor Lamp Desk Lamp Kitchen Chair Living Room Chair Object Hierarchy from Rosch Furniture

19. Phobic Sociopath Claustro-phobic Acro-phobic Hydro-phobic Rapist Strangler Torturer Trait Hierarchy fromCantor and Mischel Emotionally Unstable

20. Models of Representation • Associative network models - • Concepts are connected to each other presumably in the nervous system as well • When one concept is activated this activation spreads to other concepts to which it is connected • Parallel-constraint models • Connections can not only lead to activation they can also lead to inhibition • When a concept is activated enervation is spread around along these links until a stable state emerges

21. Protests unfair treatment Wants nice house Won’t pay rent until house painted Aggressive Curses Hits Punches Asian Lawyer Well dressed Competitive intelligent Spreading Activation Network

22. Protests unfair treatment Wants nice house Won’t pay rent until house painted Aggressive Curses Hits Punches Asian Lawyer Well dressed Competitive intelligent Parrallel-Constraint-Satisfaction Model