Planning a Study

Lawrence R. Gordon

Psychology Research Methods I

Research Project

Your opportunity to do original research! Timeline

– Week 8 (making groups (note on social loafing), picking topics)

– Week 9 (planning project)– Week 10 (design and consent forms)– Week 11 (collect data)– Week 12 (analyze data)– Presentations and Papers (report data)

What can you do?

Correlational research– usually by survey– testing relationship of one measured variable

with a second measured variable

Experimental research– these are strongly encouraged– need to manipulate IV(s)– keep all else constant

But remember the timeline!

Experiments are time consuming Watch for manipulation failure Experiments can be difficult (depending on

how you manipulate the IV) Need good control

Some Model Experiments - IDEA

Using surveys to manipulate the IV Wordings of surveys are altered to

manipulate the IV Surveys are randomly distributed

(“assigned”) to the participants Compare responses on one form of the

survey to another form of the survey Only your manipulation is different

Dr. Jones' "Student Ratings" Scale...

BY Sex x Time

Dr. Jones' sex...

'him''her'

Mean S

tud

ent R

atin

g S

cale

(6r)

5.4

5.2

5.0

4.8

4.6

Professional psychol

Unspecified

10 years

30 years

Pros and Cons of Survey Experiments Pros

– Quick

– Easy

– Reduces experimenter interaction

– Improves control

Cons– May need to pilot test

the items

– Participants may not be as attentive

– Manipulation may not be as salient

– Self-reports

– Be careful of wording! (Goodwin, App B: 459-466)

How much TV do you watch?

Effects of response options on reports of television watching

The same question was asked on all surveys, but the response options were manipulated

It was expected that the possible options would influence the responses

“How much TV do you watch daily (in minutes)?” The seven response options were different on

the 2 forms of the survey Form A

– “up to 60 minutes” were the first 5 options– the highest response was “more than 90”

Form B– “up to 60 minutes” were the first 3 options– the highest response was “more than 180”

Hypotheses

If “more than 60” was a more extreme response option, then fewer participants would report watching this much TV compare to others for whom “more than 60” was not as extreme a response

(What is the null hypothesis?) Results?

Reports of TV watching by Survey Form (1999)

84.1

15.9

68.6

31.4

0

20

40

60

80

100

Up to 60 More than 60

Percent

Form AForm B

Reports of TV watching by Survey Form (2002)

Less than vs. More than 60

Over 60Up to 60

Pe

rce

nt

100

80

60

40

20

0

TVFORM

more than 90

more than 180

The TV Survey Study In 1999, participants reported watching

more than 60 minutes of TV daily less frequently when these responses were more extreme (p = .018)

In 2002, participants again reported different rates of watching TV depending on the response sets (p = .038)

Can we infer that this is a causal relationship?

Is this a true experiment?

Other Experiments: Memory

Independent variables– Presentation (verbal, visual, episodic, semantic,

procedural)– Information (meaningful, meaningless (cvc

syllables like “POF”), emotional content)– Mnemonic strategies– Interference– Recall type (recognition, production)

Memory Experiments (cont.)

Independent variables (cont.)– Time before recall– Time between trials– Serial position (primacy and recency effects)– Presentation rate– Number of trials (proactive interference, e.g.

Homer’s quote)• “But every time I learn something new, it pushes

out something old! Remember that time I took a home wine-making course and forgot how to drive?”

Trial 1, first seven

Circle these if you wrote them down– tie– chair– clown– scarf– grass– bat– pig

Trial 1, second seven

Square these if you wrote them down– stool– door– milkmaid– window– fly– cow– couch

Trial 1, third seven

Underline these if you wrote them down– horse– wren– house– cowboy– tree– shrub– banana

Trial 2, first seven

Circle these if you wrote them down– dog– glove– store– lake– newspaper– wrench– bush

Trial 2, second seven

Square these if you wrote them down– book– cat– flower– mitten– nail– laundry– ocean

Trial 2, third seven

Underline these if you wrote them down– mushroom– diary– saw– mouse– jail– coat– river

Scoring

Count up number of circled, squared, underlined, and “extra” words for each trial and record

Add up totals for each trial Add up totals for each “third” Make sure that you write your name and the

date on this sheet to pass in so that you will get credit for this class!

Other examples of projects

Using published measures Replication studies Something else that interests you? If you

(and your TA) think you can pull it off, go for it! You are not graded on the effects you find, but your design must be realistic and well conducted.