1. Non-Experimental designs: Surveys & Quasi-Experiments
Psych 231: Research Methods in Psychology

2. Lab attendance is critical this week because group projects are being administered
Attendance will be taken.
Turn in the group project rating sheet 1 after you have run your experiments (Monday is okay)
Announcements

3. Non-Experimental designs
Sometimes you just can’t perform a fully controlled experiment
Because of the issue of interest
Limited resources (not enough subjects, observations are too costly, etc).
Surveys
Quasi-Experiments
Developmental designs
Small-N designs
This does NOT imply that they are bad designs
Just remember the advantages and disadvantages of each
Non-Experimental designs

4. Surveys What are they? Why conduct them?
Questionnaires and interviews that ask people to provide information about themselves
Why conduct them?
To compliment experimental work
Good/common first step, can collect a lot of data about a lot of variables
Do not have to directly observe behaviors
Best way to collect some kinds of information:
Descriptive, behavioral, and preferential
e.g., demographic information, recreational behavior, and attitudes
Surveys

5. Advantages
One can investigate internal events (for example, attitudes & opinions)
Can generalize about an entire population based on relatively small samples of individuals
Large amounts of data can be collected quickly with relatively little cost (effort, time, etc.)
But they’re often not as “cheap” as you may think
Surveys

6. Surveys Disadvantages Correlational: causal claims shouldn’t be made
Non-response bias
Why doesn’t everybody respond?
Does response rate interact with variables of interest?
Large data sets are sometimes difficult to analyze
Self-reports may not be truthful
Response set - tendency to respond from a particular perspective (e.g., how a “moral” person would answer)
Surveys

7. Stages of survey research
Stage 1) Identify the focus of the study and select your research method
What are the objectives of the research?
Is a survey method the best approach?
What kind of survey should be used?
Group administration
Mail surveys
Internet surveys
Telephone surveys
Face-to-face interviews
Focus group interviews
Stages of survey research

8. Stages of survey research cont.
Stage 2) Determining the research schedule and budget
Stage 3) Establishing an information base
Find out what’s been done, what’s known
E.g., Find other related surveys
Stage 4) Identify the sampling frame
The actual population that the sample is drawn from (as opposed to the ideal population)
Think of it as operationalizing the conceptual level population
Stages of survey research cont.

9. Stages of survey research cont.
Stage 5) Determining the sample method and sampling size
Review Probability and Non-Probability methods
Voluntary response method
Importance of sample size
Stages of survey research cont.

10. Voluntary response methods
A kind of convenience sampling methods commonly used
Should leftover Halloween candy be given out
to students who get an A on the exam?
Call 123-NONO if you think NO
Call 123-4YES if you think YES
Problem: Typically only individuals with strong opinions respond, so the results are often extremely biased
Voluntary response methods

11. Importance of sample size
Sampling error - how is the sample different from the population?
Confidence intervals
An estimate of the mean or percentage of the population, based on the sample data
“John Doe has 55% of the vote, with a margin of error ± 3%”
Margin of error (that “± 3%” part)
The larger your sample size, the smaller your margin of error will be.
Which would you be more likely to believe
“We asked 10 people …”
“We asked 1000 people …”
Importance of sample size

12. Importance of sample size
Sampling error - how is the sample different from the population?
Response rate
What proportion of the sample actually responded to the survey?
Hidden costs here - what can you do to increase response rates
Non-response error (bias)
Is there something special about the data that you’re missing (From the people who didn’t respond)?
Importance of sample size

13. Stages of survey research cont.
Stage 6) Designing the survey instrument
Question construction: How the questions are written is very important
Clearly identify the research objectives
Do your questions really target those research objectives (think Internal and External Validity)?
Take care wording of the questions
Keep it simple, don’t ask two things at once, avoid loaded or biased questions, etc.
How should questions be answered (question type)?
Stages of survey research cont.

14. Good and poor questions
Was the FDC negligent
by ignoring the warnings
about Vioxx during testing
and approving it for sale?
Yes No
Unsure
If the FDC knew that
Vioxx caused serious
side effects during testing,
what should it have done?
Ban it from ever being sold
Require more testing before approving it
Unsure
Problem: emotionally
charged words
Good and poor questions

15. Good and poor questions
Are you against same sex
marriage and in favor of a
constitutional amendment
to ban it?
Yes No
Unsure
What is your view on same sex marriage?
I think marriage is a matter of personal choice
I’m against it but don’t want a constitutional amendment
I want a constitutional amendment banning it
Problem: Biased in
more than one direction
Problem: Asks two
questions
Good and poor questions

16. Survey Questions Question types
Open-ended (fill in the blank, short answer)
Can get a lot of information, but
Coding is time intensive and potentially ambiguous
Close-ended (pick best answer, pick all that apply)
Easier to code
Response alternatives are the same for everyone
Rating scales
Used for “how much” judgments
e.g., measures attitudes, agree/disagree
Take care with your labels
Range of scores, anchors
Survey Questions

17. Stages of survey research cont.
Stage 7) Pre-testing the survey instrument
Fix what doesn’t seem to be working
Stage 8) Selecting and training interviewers
For telephone and in-person surveys
Need to avoid interviewer bias
Stage 9) Implementing the survey
Stage 10) Coding and entering the data
Stage 11) Analyzing the data and preparing a final report
Stages of survey research cont.

18. Quasi-experiments What are they? General types
Almost “true” experiments, but with an inherent confounding variable
General types
An event occurs that the experimenter doesn’t manipulate
Something not under the experimenter’s control
(e.g., flashbulb memories for traumatic events)
Interested in subject variables
high vs. low IQ, males vs. females
Time is used as a variable
Quasi-experiments

19. Quasi-experiments Advantages Disadvantages
Allows applied research when experiments not possible
Threats to internal validity can be assessed (sometimes)
Disadvantages
Threats to internal validity may exist
Designs are more complex than traditional experiments
Statistical analysis can be difficult
Most statistical analyses assume randomness
Quasi-experiments

20. Quasi-experiments Program evaluation
Research on programs that is implemented to achieve some positive effect on a group of individuals.
e.g., does abstinence from sex program work in schools
Steps in program evaluation
Needs assessment - is there a problem?
Program theory assessment - does program address the needs?
Process evaluation - does it reach the target population? Is it being run correctly?
Outcome evaluation - are the intended outcomes being realized?
Efficiency assessment- was it “worth” it? The the benefits worth the costs?
Quasi-experiments

21. Quasi-experiments Nonequivalent control group designs
with pretest and posttest (most common)
(think back to the second control lecture)
participants
Experimental
group
Control
Measure
Non-Random
Assignment
Independent Variable
Dependent Variable
But remember that the results may be compromised because of the nonequivalent control group (review threats to internal validity)
Quasi-experiments

22. Quasi-experiments Interrupted time series designs
Observe a single group multiple times prior to and after a treatment
Obs Obs Obs Obs Treatment Obs Obs Obs Obs
Look for an instantaneous, permanent change
Variations of basic time series design
Addition of a nonequivalent no-treatment control group time series
O O O T O O O & O O O _ O O O
Interrupted time series with removed treatment
If treatment effect is reversible
Quasi-experiments

23. Next time Go to labs this week, attendance will be taken
Non experimental designs cont.
Reminder, journal summary 2 assignment is coming up
Next time