Chapter 11
Testing and Individual Differences
Nothing ‘bout me! - Sting
Epilogue (Nothing ‘bout me) - Sting
Lay my head on the surgeon's table
Take my fingerprints if you are able
Pick my brains pick my pockets
Steal my eyeballs and come back for the
sockets
Run every kind of test from A to Z
And you'll still know nothing 'bout me
You don't need to read no books on
my history
I'm a simple man, it's no big mystery
In the cold weather, a hand needs a
glove
At times like this, a lonely man like me
needs love
Run my name though your computer
Mention me in passing to your college
tutor
Check my records check my facts
Check if I paid my income tax
Pore over everything in my C.V.
But you'll still know nothing 'bout me
You'll still know nothing 'bout me
Search my house with a fine tooth
comb
Turn over everything 'cause I won't be
at home
Set up your microscope and tell me
what you see
You'll still know nothing 'bout me
How Do We Measure
Individual Differences?
Measuring individual
differences is an essential
component of psychology, but
strict guidelines and ethical
standards must be followed to
ensure results and conclusions
are valid and appropriate
Test Validity - A property exhibited by a test
that measures what it proposes to measure
Face Validity – Looks like
it tests what it’s supposed
to or claims to test
Content Validity –
Contains a representation
of the larger body of
knowledge
Test Validity - A property exhibited by a test
that measures what it proposes to measure
Item Analysis – Each
question on the test is
checked to make sure it
matches the test objectives
Criterion Validity – The
test is measured against
an overall goal or
proficiency (meeting the
criteria).
Test Reliability - A property exhibited by a test that
yields the same results over time
Test-Retest Reliability – If you
take a test again, you should
get the same or similar results.
Split-Half Reliability – The test is
split into two equal parts (oddeven) and scores are compared.
Copyright © Allyn & Bacon 2007
Test Reliability - A property exhibited by a
test that yields the same results over time
Inter-rater reliability
A method of reliability
to ensure how similarly
two different test
scorers would score a
test
Standardization and Norms
(See Chapter 2 notes for
review!)
Standardized Tests and
Norms
Scientists use statistics to
establish a normal curve
1. Administration and
scoring guidelines are
the same for each
person who takes the
test (e.g. SAT’s,
CAHSEE)
This curve can be used to
describe most phenomena
Normal range –
Scores falling near the
middle of a normal
distribution
2. Results are used to draw
inferences from.
The Exceptional Child
Average Range – Often
conceived as representing the
portion within 1 SD above and
below the mean (68% of the
scores).
Mental retardation/
Cognitively Deficient –
Often conceived as
representing the lower 2% of
the IQ range
Above Average and Below
Average – Often conceived as
representing the portion within
2 SD above or below the mean
(the 14% on either side).
Giftedness –
Often conceived as
representing
the upper 2% of the IQ range
Normal Distribution
Mean
68% of values
95% of values
99% of values
% of scores
Standard
Deviations from
the Mean
Percentiles
Z Scores
2%
-4
-3
0
14%
-2
2nd
34%
-1
16th
-4
-3
-2
-1
60
70
80
90
34%
0
50th
0
100
14% 2%
+1
84th
+1
110
+2
98th
+3
+4
100th
+2
+3
+4
120
130
140
Wechsler Intelligence Test
Types of Tests
Objective tests
Types of Tests
Subjective tests
Ethics and Standards in Testing
Ethical concerns related to testing involve:
The confidentiality of the test results
How to report the results
How to use the test to compare individuals
The impact of tests on society as a whole
How is Intelligence
Measured?
Intelligence testing has a
history of controversy, but
most psychologists now view
intelligence as a normally
distributed trait that can be
measured by performance on
a variety of tasks
How is Intelligence
Measured?
Binet-Simon Test calculated a child’s mental age
and compared it to his or her chronological age
In America, testing became widespread for the
assessment of Army recruits, immigrants, and
schoolchildren
The Stanford-Binet Intelligence Scale is the most
respected of the new American tests of
intelligence
How is Intelligence
Measured?
Intelligence quotient –
Mental Age is the score the person receives on the test
to show what they are cognitively able to do.
Chronological Age is the age of the person at the time
of testing.
The original IQ calculation was abandoned in
favor of standard scores based on the normal
distribution
What Are the Components
of Intelligence?
Some psychologists believe
that the essence of
intelligence is a single,
general factor, while others
believe intelligence is best
described as a collection of
distinct abilities
What Are the Components
of Intelligence?
Savant Syndrome –
Copyright © Allyn & Bacon 2007
Psychometric Theories of Intelligence
g Factor –
A general ability, proposed by Spearman
as the main factor underlying all
intelligent mental activity
Psychometric Theories of Intelligence
Crystallized intelligence –
Fluid intelligence –
Cognitive Theories of Intelligence
Sternberg’s Triarchic Theory
Gardner’s Multiple Intelligences
Copyright © Allyn & Bacon 2007
Sternberg’s Triarchic Theory
Practical
Intelligence
Analytical
Intelligence
Creative
Intelligence
Sternberg’s Triarchic Theory
Practical
Intelligence
Analytical
Intelligence
Creative
Intelligence
Sternberg’s Triarchic Theory
Practical
Intelligence
Analytical
Intelligence
Creative
Intelligence
Sternberg’s Triarchic
Theory
Practical
Intelligence
Analytical
Intelligence
Creative
Intelligence
Gardner’s Three New Intelligences
Naturalistic intelligence
Spiritual intelligence
Existential intelligence
Cultural Definitions of Intelligence
Cross-cultural
psychologists have
shown that
“intelligence” has
different meanings in
different cultures
How Do Psychologists
Explain IQ Differences
Among Groups?
While most psychologists
agree that both heredity and
environment affect
intelligence, they disagree on
the source of IQ differences
among racial and social
groups
Copyright © Allyn & Bacon 2007
How Do Psychologists Explain IQ
Differences Among Groups?
Hereditarian arguments maintain that
intelligence is substantially influenced by
genetics
Environmental approaches argue that
intelligence can be dramatically shaped
by influences such as
• Health
• Economics
• Education
Heritability and Group Differences
Heritability –
Heritability says nothing about betweengroup differences
Imagine that seeds from the same mixture are sown in normal and
deficient soil. Although height differences within each box will be
genetic (high heritability), the height difference between groups
will be environmental, and heritability will be lower, because we
will never know what the potential for their height could have
been.
Heritability and Group Differences
Research with twins and adopted children
shows genetic influences on a wide
range of attributes, including intelligence
Research has also shown that racial and
class differences in IQ scores can be
eliminated by environmental changes
End of Chapter 11