measuring the person © copyright 2006 allyn & bacon mayers personality: a systems approach part...

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Measuring the Person

Theme and Variation on

Topic 2. Research In Personality

This multimedia product and its contents are protected under copyright law. The following are prohibited by law:• any public performance or display, including transmission of any image over a network;• preparation of any derivative work, including the extraction, in whole or in part, of any image;• any rental, lease, or lending of the program.

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Comparison to Personality: A Systems Approach…

• Chapter 2: Research in Personality 1. Where Do Data Come

From?*

2. What Research Designs are Used in Personality?

3. What Does it Mean to Measure Personality?

4. How do Psychologists Study So Many Variables?

• Lecture 2: Measuring the Person1. Collecting data

2. Measuring the person1. Reliability

2. Validity

3. Simplifying multiple measures

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Gathering Data about the Person

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Molecular-Molar Dimension (Review)

Molar (e.g., sociological level)

Intermediate (e.g., psychological level)

Molecular (e.g., biological level)

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Personality and Its Position: ReviewMolar (e.g., sociological)

The Incorporative Environment

Intermediate (e.g., psychological)

The Personality System

The Situation

Molecular (e.g., biological)

The Brain and Nervous System

The Setting

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Two Main Sources of Data Molar The Incorporative Environment

Intermed-iate The Personality System

The Situation

Molecular The Brain and Nervous System

The Setting

• External source data – from outside the person• Personal report data – from inside the person

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

External Source Data: ExamplesMolar (e.g., sociological)

Institutional Data (School records, Marriage certificates)

Intermediate (e.g., psychological) Personality

Informant Data (What a friend says about you)

Molecular (e.g., biological)

Biological Data (Medical records)

Setting Data: (Neighborhood qualities)

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Major Types of Personal Report Data Molar The Incorporative Environment

Intermed-iate The Personality System

The Situation

Molecular The Brain and Nervous System

The Setting

Self-Judgment Agreeing or disagreeing with a given statement about oneself

Convergent-Report Constructing a response that meets a criterion

Thematic-Report Creating responses that reflect themes or ideas

Process-Report Pertaining to something going on in your mind at the moment

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Measuring the Person (Psychometrics)

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Review of Correlation

• Correlation co-relates…

• It relates one variable to another

• The size of the correlation indexes the strength of the relationship r = 1.0 is a perfect positive relationship r = 0 is no relationship r = -1.0 is a perfect negative relationship

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Measurement of Attributes

• Measure attributes of the object

• For example, measurement of– length (to right)– weight (to right)

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Psychometric Theory

A. Theories of how to measure abstract, mental phenomena

B. The central equation:X = T + e

X, the obtained test scoreT, the true scoree, the error score

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Reliability in Physical Measurement

Things to Remember Measuring a Window for Window Blinds:

• Use a steel tape for accuracy. • Measure the exact width of the window at 3

different places. • Make all measurements to the nearest 1/8 inch.

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Definitions of Reliability

• Informal: that a test measures what it measures with consistency

• Formal: the correlation, r, between the true score and the obtained score.

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

(A hard) Pop Question

When is a mental test perfectly reliable?

A. X = 0

B. T = 0

C. e = 0

D. X = T

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Measurement Validity

A. Definition: That a test measures what it is supposed to measure

B. Types of Validity:1. Content

2. Criterion

3. Structural

4. Construct

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Content Validity

A test’s items accurately sample from the content domain

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Criterion (or Predictive) Validity

A test predicts a specific, measurable outcome, such as a life variable

Examples:

marriage

grade point average

occupational success

(or postdicts it, or concurrently indicates it)

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Pop Question

A. Which of the following correlations between two variables is most useful for the purposes of predicting one from the other?

a) -.75

b) .00

c) +.25

d) +.50

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Structural Validity

• A test measure the number of things it claims to measure

• Technical Test: Factor Analysis…– How many factors does a test measure? – Factor: An “underlying” variable

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Construct Validity

• A test behaves the way it is supposed to behave according to theoretical statements, over numerous circumstances and tests

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Handling Multiple Variables

This multimedia product and its contents are protected under copyright law. The following are prohibited by law:• any public performance or display, including transmission of any image over a network;• preparation of any derivative work, including the extraction, in whole or in part, of any image;• any rental, lease, or lending of the program.

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Multiple Variables

• Personality is a complex, multifaceted system

• This means that a lot of variables may be examined at a time

• How does one cope?

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Multivariate Techniques

• Multivariate techniques handle multiple variables

• One crucial kind of technique examines “how many things” are being measured

• This class of techniques includes:– Factor analysis (the example here)– Multidimensional scaling– Cluster analysis

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Logic of Factor Analysis

• Factor analysis uses correlational logic– If multiple variables correlate highly, they are

the same thing– If the variables don’t, they are different things

• Example:– If happiness and joy correlate highly: the

same– If they don’t: different

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

1. What does a factor look like?

I am: I

Curious .40

Interested .60

Thoughtful .80

Bored -.40

• The test items from the original test are in the left-most column

• A factor is represented by a column of factor loadings under a roman numeral

• The factor loading is the correlation between a test item and a factor

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Simplified Rules for Interpreting a Factor• Step 1: Identify original test items with high

positive loadings • Step 2: Ask, what are the items trying to “get at”?

(That’s the primary name of the factor). (e.g., extraversion)

• Step 3: Locate the items loading negatively on the same factor. Those tell you the “polar opposite” label (e.g., introversion) – if there is one

• Step 4: No high loadings? Then, the factor is a “garbage” factor.

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Example A

I II• Do you like parties? .70 -.15• Are you often nervous? .30 .80

Are you sociable? .75 -.01• Do you prefer to read over -.70 -.09

going to parties?• Are you often in a bad mood? .04 .70

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Example B

I feel… I II III

Happiness .80 .20 .01

Sadness -.70 .10 .05

Excitement .60 .75 -.10

Anxiety -.25 .40 -.15

Calm .20 -.50 .20

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

Example C

I can be described as I II III

conscientious .80 .20 .01

often late -.70 .10 .05

warm .20 .75 -.10

friendly -.25 .40 -.15

cold -.20 -.50 .20

Measuring the Person

© Copyright 2006 Allyn & Bacon Mayer’s Personality: A Systems Approach

PART 1: EXPLORING PERSONALITY CHAPTER 2: RESEARCH IN PERSONALITY

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