1. Chapter 2
Research Approaches and Methods
of Data Collection
9/6/2012

2. Roadmap
• Reading Quiz
• Announcement about labs
• Helpful resources update
• Chapter 2 Material
– Variables in quantitative research
– Experimental research
– Nonexperimental research
– Qualitative research
– Major data collection methods

3. Suggestion:
To help you get in the psychological scientist
mindframe, check out:
www.psychologicalscience.org
APS on facebook
Follow PsychScience on Twitter

4. Reading Quiz:
Your own paper. Name and date.
Write letter of correct answer for each question.
1. A variable that varies in type or kind is called a(n)
a. Categorical variable c. Independent variable
b. Dependent variable d. Intervening variable
2. The strongest evidence for causation comes from
which of the following research methods?
a. Experimental c. Correlational
b. Natural manipulation d. All of the above

5. Lab Announcement
• If you are in one of these labs:
– PSYC 2950.302 Stephanie Womack Mon. 12:00 – 1:50 PM
– PSYC 2950.303 James Garcia Thur. 4:00 – 5:50 PM
– PSYC 2950.304 Elizabeth Jenkins Mon. 2:00 – 3:50 PM
– PSYC 2950.311 Sean Lewis Thur. 6:00 – 7:50 PM
• Please consider switching to one of these labs:
– PSYC 2950.310 Daniel Romero Wed. 5:30 – 7:20 PM
– PSYC 2950.312 Megan Purser Fri. 10:00 – 11:50 AM
• Procedure:
– E-mail your current lab instructor ASAP.
– Psychology Dept. will e-mail to confirm if you are moved.

6. Helpful Resources
• Tutors:
– Beth, Cesar, Jeff
– Hours every day M-F in Terrill Hall 215
– Info on Blackboard
• Librarian Pat Reese
– “office hours” Mondays and Thursdays
– Terrill Hall 383
– Info on Blackboard

7. Now let’s dig in to Chapter 2 material!
• Overview of different research approaches
• In later chapters we will break down details of
experimental and other research designs

8. Broad Categories of Research Design
• Quantitative – numerical data
• Qualitative – non-numerical data
• In psychology, the focus has traditionally been
on quantitative

9. Variables in Quantitative Research
• Variable - Any characteristic of a phenomenon
that can vary (differ) across organisms,
situations, or environments.

10. Types of Variables
• Categorical Variable - comes in whole units or
categories
– Groups / categories
• Continuous Variable - forms a continuum and
can be represented by fractional and whole
units
– Text calls this “Quantitative Variable”

11. Roles Played By Variables
• Independent Variable (IV) - an antecedent
condition manipulated by the researcher
• Dependent Variable (DV) - measures the
influence of the independent variable
– Effect
– Outcome measure
• See Table 2.1, p. 31 for a good overview

12. Examples
• Study of the impact of different amounts of study time on
students exam grades.
– What is IV?
– What is DV?
• Study of the effect of stress on recall for studied list of words
– What is IV?
– What is DV?

13. Other Roles Played by Variables
• Mediating Variable
• Moderating Variable
• Extraneous Variable

14. Mediating Variable (Mediation)
Mediator operates between two other variables in a
chain of causation.
Distracting Thoughts
Anxiety Performance on
Memory Task

15. Moderating Variable (Moderation)
• The relationship between an IV and DV
depends on the level of some other variable
• Think interaction (ANOVA)

16. Moderation example
• client gender and therapy outcomes
– Women better outcomes with female therapist
– Men better outcomes with male therapist
– Therapist gender is a moderating variable
• Do men or women have better therapy
outcomes?
• It depends on the therapists’ gender

17. Extraneous Variable
• A.K.A. confounding variable or third variable
• Competes with the IV in explaining the
DV/outcome
• Example:
– Ice cream sales positively correlated with violence
– What’s going on?

18. TYPES OF QUANTITATIVE RESEARCH

19. Experimental Research Approach
• Approach to take when we want to
investigate/determine causation
• Think “cause = experiment”

20. 3 required conditions for claiming
causation
1. Relationship condition
Variable A (IV) must be related to variable B (DV)
2. Temporal order condition
If A is the CAUSE of B, changes in A must precede
changes in B.
3. No alternative explanation condition
No plausible alternative explanations for the cause of B
exist.

21. The Psychological Experiment
• An “Objective observation of phenomena that
are made to occur in a strictly controlled
situation in which one or more factors are
varied and the others are kept constant”
(Zimney, 1961, p 18).

22. Elements of an Experiment
• Objective observation
• Of phenomena that are made to occur
– Manipulation
• In a strictly controlled situation
– One or more factors are varied
– Others are kept constant

23. Example of an experiment
Treatment Posttest
Random XT Y
Assignment
to XC Y
condition

24. Advantages of Experimental Designs
1. Causal Inference- Can attempt to determine
cause
2. Control over extraneous variables
3. Ability to manipulate variables

25. Disadvantages of Experimental Design
1. Only tests effects of manipulated variables
2. Can seem artificial/contrived
3. Inadequate method of scientific inquiry on its
own

26. Experimental Research Settings
• Field Experiments
• Laboratory Experiments
• Online Experiments

27. Field Experiment
• conducted in a real-life setting
• Manipulate variables and control the influence
of as many extraneous variables as possible.
• Observation in real world, not in a contrived
lab setting.

28. Advantages
• You may be able to observe the impact of a
variable in a real-world setting but not in a
laboratory
– Examples?

29. Laboratory Experiment
• conducted in the controlled environment of a
laboratory.
• Able to control all or nearly all extraneous
variables
• Can manipulate one or more other variables of
interest.

30. Benefits
• Potential better measurement ability in a lab
than in a field setting.
• Some things are not able to be observed in a
field setting.

31. Internet Experiments
• In order to still be an “experimental study”
something MUST be manipulated.
• Simply giving a survey to everyone and looking
at correlations between measures is not
“experimental”

32. • Benefits- Cheap, easy, fast, high power
– Easy to access diverse populations
– Bring experiment to participant
• Problems- lack of control, self-selection,
dropout, multiple submissions

33. Does it all have to be Experimental?
• No--Other research designs are commonly
used
• All of these tell us something unique

34. Quantitative vs. Qualitative
• Quantitative research uses numerical data to
answer a research question
• Qualitative research uses non-numerical data
to answer a research question
– What is non-numerical data?
– How can this help Experimental research?