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
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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
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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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