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Sept. 5, 2014 METHODS FOR

STUDYING PSYCHOLOGY

Reading for Monday: Stanovich Ch. 3

Turn in the questionnaire I handed out at the beginning of class This is part of your grade for Recitation #1 Can also be found on the Canvas -> Pages -> Recitations

Our first Recitation will begin on Wednesday (and carry over to Friday) You need to be present both days to get full credit

HOUSEKEEPING

CASE STUDIES Observations from case studies can provide

useful ideas for future research They cannot be generalized to a larger

population Smokers die younger than non-smokers

Anecdote: My grandfather smoked 1 pack a day and lived to be 94

Can be vivid and lead to false conclusions

NATURALISTIC OBSERVATION Recording behavior in the natural

environment (no manipulation) Does not control for outside factors that

influence behavior

DESCRIBING BEHAVIOR

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SURVEYS A way to assess self-reported attitudes and behaviors of a group Often uses a representative and random sample Used to:

Gather Opinions

Dispel Myths: Empty Nest Syndrome (Rubin, 1979) Discover Possible Relationships:

Physical Punishment and Aggression in Children (Lansford et al., 2005)

DESCRIBING BEHAVIOR

Would you vote for one of these candidates? How does a community feel about crime?

WORDING EFFECTS Choose words carefully Keep questions short and simple Use precise terminology Avoid unnecessary negatives Avoid unwarranted assumptions Ask only one question at a time (double-barreled questions)

RANDOM SAMPLE To generalize we need a representative sample Can use random sampling

Everyone in the population has the same chance of being included Ex: Population is 1000; Randomly select 100 people

Are there possible problems even when using this survey strategy?

SURVEYS

Some real world relationships: As ice cream sales increase homicide rates increase

As the number of churches increase in an area the number of prostitutes increase

The increased sales of organic food in the US has increased with the rates of autism in US

CORRELATIONS

Are these relationships causal? Is there something else that might account for the relationship?

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CORRELATIONS AND COEFFICIENTS

A correlation is a measure of the extent to which two factors vary together (relate), and thus how well one factor predicts the other

Measured by the correlation coefficient, a statistical index of the relationship that goes from +1.0 to -1.0

Number (0 to 1.0) tells us the strength of the relationship

Sign (+ or -) tells us the direction of the relationship Positive: Both variables increase or decrease together Negative: One variable increases while the other decreases

CORRELATIONS AND COEFFICIENTS

Correlations are often grouped into scatterplots a cluster of dots, each of which indicate the values of two variables. The slope of a scatterplot suggests the relationship between the variables (positive, negative, or none)

DROPPED WALLET TEST

Subject Age Amount of $ returned ($5.00)

1 15 $0

2 55 $5.00

3 62 $4.00

4 24 $2.00

5 70 $5.00

6 33 $3.00

7 35 $2.00

8 21 $0

9 47 $3.00

10 53 $3.00

Inspired by data from Paul Kinsella, wallettest.com

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DROPPED WALLET TEST

What type of relationship does this show? What conclusion might we draw?

CORRELATION AND CAUSATION

Age correlates with an amount of money returned from a lost wallet (honesty) So, does being older cause a person to be more honest?

Age Honesty

Age Honesty

Honesty Age

Honesty

Age

Factor X

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CORRELATION AND CAUSATION

Correlation can only indicate the possibility of causation

Knowing that two events are associated does not mean that one causes the other

Correlation is not causation

Illusory correlations are perceived but unreal correlations Getting chilled and wet does not cause people to catch a cold Illusory pattern perception

Can help explain how superstations develop You notice that you play an amazing game while wearing a certain pair of socks When worn again similar results (there is no real relationship here only an illusory

one)

EXPERIMENTATION AND CAUSATION

Does getting older really cause people to be more honest?

Experimentation needs to involve random assignment of groups

Can you randomly assign someone to be young or old? Difficult to test experimentally

Sometimes correlational studies are necessary Ethics What things might need to be tested using a correlation?

Other factors that can be tested by random assignment?

EXPERIMENTAL GROUPS

The experimental group is the group that is exposed to the treatment of interest

The control group is the group that is not exposed to the treatment of interest; serves as a comparison for evaluating the treatment

Many times, a double-blind procedure can be used in experimentation (the research participants and the research staff are unaware about which research participants are which Why use double-blind?

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DOUBLE BLIND TESTING AND CLEVER HANS

INDEPENDENT VS. DEPENDENT VARIABLES

Group Dependent

Variable Independent

Variable

Random Assignment!!!

Independent Variable The factor(s) that is/are being controlled independently of other factors by the experimenter Dependent variable Measure of behavior(s) which could vary dependently upon the experimental factor

No Social Training Control

Experimental

Honesty Score

Social Training

Honesty Score

DEFINITIONS

A variable is anything that can vary Intelligence, personality scores, TV exposure, walking speed

anything that is feasible (and ethical)

An independent variable is manipulated by the experimenter to test the difference between the experimental group and the control group

The dependent variable is measured by the experimenter to test the effect of the independent variable

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EXAMPLE

A researcher places a sign in some hotel rooms that says, Many guests who have used this room decided to refuse new towel service in an effort to save the environment. The researcher found that 60% of hotel guests in rooms with such a sign refused new towel service, compared to 25% of guests in rooms with no sign.

What is the independent variable? What is the dependent variable?

SUMMARY

Descriptive studies , l ike case studies, naturalistic observation, and surveys, lend useful information towards predictions if behaviors seem related to each other

If behaviors relate to each other in a predictable way, we say that they correlate. Correlations may be positive or negative (or, no correlation may exist)

Correlations are not causations!

Causation may be tested by experiments which use random assignment of groups to control for any factors other than the one being tested

Experiments test the effect of at least one experimenter-controlled independent variable on one measureable dependent variable