Exam #2 (1 of 2) Flashcards
LABORATORY EXPERIMENTS
LABORATORY EXPERIMENTS
Laboratory experiments: Advantages
Advantages of laboratory experiments:
- Establish causation
- Experimental control (lot of control over environment)
- Usually high internal validity
Laboratory experiments: Disadvantages
Disadvantages of laboratory experiments:
- Many IVs of interest can’t be manipulated
- External validity is a concern (poor generalizability)
- Possibility of oversimplification (may end up missing many relevant variables)
Two main types of laboratory experiments
Two main types of laboratory experiments:
-
Impact experiment
* Participants = active participants in series of events. They react to these events as they occur
* Very involving
* Usually one person at a time -
Judgment experiment
* Participants recall, recognize, classify, etc. materials presented by experimenter
* Less involving, less investment
* Usually easier to do
* Can have multiple people at a time
- Researchers can convert impact experiments to judgment experiments, vice versa
- Impact or judgment? Depends on research Q’s
mundane realism
mundane realism = the extent to which events occuring in the research setting are likely to occur in the normal course of participants’ lives
- many laboratory experiments don’t have high mundane realism
- not the most important kind of realism
- example of laboratory experiment with high mundane realism: reading a newspaper article and answering questions about it
experimental realism
experimental realism = extent to which the experiment is involving to the participants and is taken seriously by them
- more important than mundane realism
- Impact studies –> usually high experimental realism
- Judgment studes –> usually lower experimental realism
- It takes researcher skill to create experimental realism
Psychological realism
Psychological realism = the extent to which the psychological processes that occur in an experiment are the same as psychological processes that occur in everyday life
- most important type of realism for increasing generalizability
Four Stages of Laboratory Experimentation
Four Stages of Laboratory Experimentation:
- Setting the stage for the experiment
- Constructing the IV
- Measuring the DV
- Planning the post-experimental follow-up
- Setting the stage
- Setting the stage:
- Researchers need to explain the research in a way that makes sense to participants
- May need a cover story = false rationale for research
Cover stories should:
Cover stories should:
* Be as simple as possible
* capture participants’ attention
* encompass all features of the experiment that satisfies curiosity so they don’t speculate on hypothesis
- (Cover stories tend to be more elaborate in impact experiments)
2. Constructing the IV
- Constructing the IV:
- How to operationalize the conceptual variable
- Pilot testing: test IV on small # of participants to see if it brings about intended state
- Manipulation check: extent to which an experimental treatment has intended effect on each participant
In short, pilot testing is about testing the overall design of the study, while manipulation checks are about confirming the effectiveness of specific experimental interventions.
What are experimenter effects
Experimenter effects = unintended influences that a researcher’s presence, behavior, or expectations can have on the results of a study
- These effects can alter participants’ responses or behaviors, affecting outcomes
What does SCC call experimenter effects?
SCC would call experimenter effects as an experimenter expectancies threat to construct validity
Avoiding experimenter effects
Avoiding experimenter effects:
- Experimenters can be kept naive to research hypothesis (especially research assistants)
- Experimenters could be kept unaware of condition assignment
- Multiple experimenters could be involved in each session, each with only limited (and different) information about the experiment
What is participant awareness bias?
Participant awareness bias = participants change behavior simply because they know they are being observed or are part of an experiment.
This self-consciousness can change responses or actions, affecting the study’s validity
What does SCC call participant awareness biases?
SCC would call participant awareness bias a reactivity to the experimental situation threat to construct validity
Avoiding participant awareness biases
Avoiding participant awareness biases:
- Can use deception or cover story
- Can use an “accident” or “whoops” manipulation
- Unrelated-experiments technique (e.g., IV manipulated in ‘first experiment,’ DV measured in ‘second experiment’)
Confederate = fake participant who performs a specific function of the study
3. Measuring the DV
3. Measuring the DV:
- Many ways to operationally define a conceptual variable
- Choice of DV depends mostly on research Q
.
Also depends on practical considerations: - Self-report
- Behavioral
- Behavioroid = measurement of behavioral intentions (what people say they plan on doing, like self-reports of self-care intentions)
- Physiological
What type of DV measurement is research about prejudice more likely to use?
Research about prejudice may rely more on behavioral measures given that people will lie about how they feel
What’s one way to hide that you’re doing a posttest?
E.g., We lost your pretest responses! Please complete again.
Ways to disguise the DV
Ways to disguise the DV:
- Embed DV within larger questionnaire (e.g., use distractor questions around central DV)
- Use unrelated-experiments technique
- Measure DV in setting that participants think is not part of the experiment
- Use the “whoops” technique (e.g., lost pretest)
- Use behavioral or physiological measures that would make it difficult for participants to alter their scores
4. Post-experimental follow-up
4. Post-experimental follow-up
- @ end of sessions, important to provide debrief
- Ensure participants are in good/healthy frame of mind
- Probe for suspicion
- Explain experimental procedures, including possible deceptions
- Learn participants’ thoughts about experiment
- Express appreciation for participants’ time and effort
MODERATORS AND MEDIATORS IN EXPERIMENTAL RESEARCH
MODERATORS AND MEDIATORS IN EXPERIMENTAL RESEARCH
What do moderators and mediators do in terms of our understanding?
Moderators and mediators help us to better understand causal effects (albeit in different ways)
What is a moderator?
A moderator is a variable that affects the strength or direction of the relationship between other variables in a study.
It essentially modfies how or to what extent these variables are related.
More facts about moderators
Moderators:
- A moderator qualifies the effect of an IV (or treatment) on a DV (or outcome)
- The moderator tells us when, for whom, or under what circumstances that causal effect occurs
- A moderator might alter the strength, direction, or existence of the effect
Moderator: qualifies | when | for whom | under what circumstances
What can moderators be?
Moderators can be:
- a variable manipulated by the researchers
- or a characteristic of participants that the researchers measure (usually a stable trait characteristic like Big-5 personality dimension)
Moderational Model (diagram)
How do moderators affect external validity?
Moderators can limit external validity. They add conditions to the effect of the IV on the DV.
What does Social Facilitation Theory relate to?
Social Facilitation Theory relates to the idea that the presence of others (IV) can have an impact on performance (DV)