Chp 1 Notes from Myers 8th edition

1. Thinking Critically with Psychological
Science
Research & Statistics
Chapter 1

2. Critical Thinking
thinking that does not
blindly accept arguments
and conclusions
Examines
discerns
evaluates
Assumptions
Hidden Values
evidence

3. Limits of Intuition
and Common Sense
Hindsight Bias
Overconfidence

4. But first…
A brief example of how NOT to
conduct an experiment care of Dr.
Venkman

6. Research Strategies
Theory
Hypothesis

7. The Scientific Method
generate or refine
research and
observations
lead to
hypothesis
theories

8. Operational Definition
Example-
IQ TESTS

9. Replication
Case Study

10. Survey
False Consensus Effect

11. Population
Random Sample

12. Research Strategies
If marbles of two
colors are mixed
well in the large
jar, the fastest
way to know
their ratio is to
blindly transfer
a few into a
smaller one and
count them

13. Naturalistic Observation
observing and recording
behavior in naturally
occurring situations
without trying to
manipulate and control
the situation

14. Correlation Coefficient
a statistical measure of the extent to which
two factors vary together and thus how well
either factor predicts the other
Correlation
coefficient
Indicates direction
of relationship
(positive or negative)
Indicates strength
of relationship
(0.00 to 1.00)
r = +.37

15. Scatterplot
–a graphed cluster of dots, each of
which represents the values of two
variables
–the slope of the points suggests the
direction of the relationship
–the amount of scatter suggests the
strength of the correlation
–little scatter indicates high correlation
–also called a scattergram or scatter
diagram

16. scatterplots
Perfect positive
correlation (+1.00)
No relationship (0.00) Perfect negative
correlation (-1.00)

17. Scatterplot of Height and
Temperament
55 60 65 70 75 80 85
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
Temperament
scores
Height in inches

18. Research Strategies
Height and Temperament of 20 Men
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
80
63
61
79
74
69
62
75
77
60
64
76
71
66
73
70
63
71
68
70
75
66
60
90
60
42
42
60
81
39
48
69
72
57
63
75
30
57
84
39
Subject
Height in
Inches
Temperament Subject
Height in
Inches
Temperament

19. Research Strategies
(1)
Low self-esteem
Depression
(2)
Depression
Low self-esteem
Low self-esteem
Depression
(3)
Distressing events
or biological
predisposition
could cause
could cause
could cause
or
or
and

20. Illusory Correlation
Illusory
Correlation
the
perceptio
n of a
relationsh
ip where
none
exists
Conceive Do not conceive
Adopt
Do not
adopt
disconfirming
evidence
confirming
evidence
disconfirming
evidence
confirming
evidence

21. Random Sequences
Your
chances of
being dealt
either of
these
hands is
precisely
the same:
1 in

22. the investigator manipulates one
or more factors (independent
variables) to observe their effect
on some behavior or mental
process (the dependent variable)
while controlling other relevant
factors by random assignment of
subjects
Experiment

23. Experiment cont.
by random assignment of
participants the experiment
controls other relevant
factors

24. Double-blind Procedure
Placebo

25. Experimental Condition
Control Condition

26. Random Assignment
**minimizes pre-existing
differences between those
assigned to the different
groups

27. Independent Variable
**the variable whose effect is
being studied
Dependent Variable
…in psychology it is usually a
behavior or mental process

28. Statistical Reasoning
Mode
Mean
Median

29. Statistical Reasoning
A Skewed Distribution
15 20 25 30 35 40 45 50 90 475 710
70
Mode Median Mean
One Family Income per family in thousands of dollars

30. Statistical Reasoning
Range
Standard Deviation
Statistical Significance

32. Positive Skew

33. Negative Skew

37. polygon

38. HISTOGRAM