Summary of the articles and ted-talks for Consumer Psychology:
Week 1:
- Aronson, E, Wilson, T., & Brewer, M. (1998). Experimentation in Social Psychology. The Handbook of Social Psychology 1:99-142. (please pick up at the marketing secretary’s office in the first week of class)
- Iyengar, S. & L...
1-1 Experimentation in Social Psychology
Aronson, Wilson and Brewer (1998)
Observational method à naturalistic behavior is systematically observed and recorded
• Valuable for generating hypotheses about the causes of social behavior.
• Poor technique for testing causal hypotheses.
Correlational method à two or more variables are systematically measured, and the
relationship between these variables is assessed.
• Inadequate for specifying cause and effect: correlation does not prove causation.
Experimental method à with this method, the researcher randomly assigns people to
different conditions and ensures that these conditions are identical except for the IV (the one
believed to have a causal effect on people’s responses).
• Main advantage: causal relationship between variables can be determined with much
greater certainty in two ways:
o By controlling all factors except the independent variable
§ Control for variation to ensure that the stimuli in experimental conditions
are similar.
o By randomly assigning people to the condition.
§ With a sufficiently large sample size, researchers can be relatively certain
the differences in the personalities or background of the participants are
distributed evenly across conditions. Any differences that are observed
are likely to be due to the IV encountered in the experiment.
Independent variable (IV) à a variable that the researcher varies to see if it has an effect on
some other variable of interest (the dependent variable).
A critical feature of experimental designs is that the situation is identical for all people except
for the independent variables of interest.
Confound: explains some or all correlation between dependent and independent variables.
Alternative explanations (for a relationship) are possible when there is a confound.
Most common objection to social psychological experiments: they seem artificial and
unrealistic.
Field versus Laboratory research:
Field studies à people are unaware that they are being studies or observed.
• Difficult to have identical situations for all people: you cannot control extraneous
variables that could confound interpretation and can contaminate the results.
• The field is regarded as more real.
Laboratory research: conducted in a laboratory, usually in such a way that people know they
are being observed or that they are in a scientific investigation.
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, • To gain enough control over the situation to be able to make causal inferences.
• Makes it easier to accomplish the random assignment of people to conditions.
• Permits the research to manipulate independent variables more precisely and to
eliminate or minimize the intrusiveness of extraneous variables.
• Ability to determine causal relationships between variables.
To really get at the heart of a problem (to understand its causes), experimental, process-
oriented studies are often the method of choice, usually conducted in the laboratory instead
of the field.
Choosing the type of experiment to perform:
• First, decide whether to design your experiment for the laboratory or the field.
o Ideally, all experimentally researchable hypotheses should be tested in both
the laboratory and the field.
• Second, decide whether the experiment is an impact or a judgment type.
o Impact experiments à people are active participants in an unfolding series of
events and have to react to these events as they occur (it is happening to the
participant).
o Judgment experiments à participants are more passive observers; they are
asked to recognize, recall, classify, or evaluate stimulus materials presented by
the experimenter (it is not happening to the participant).
Four stages of planning a laboratory experiment:
1. Setting the stage for the experiment
2. Constructing the independent variable
3. Measuring the dependent variable
4. Planning the post-experimental follow-up.
These four phases apply to both the impact experiment and the judgment experiment. The
impact experiment is more complex.
1. Setting the stage
a. Ingenuity and invention must be directed towards a credible rationale for both the
presentation of the stimulus and the collection of the data. It is about the context, or
stage, for the manipulation of the independent variable
b. Many experiments involve deception: false rationale; cover story. It needs to be
plausible.
2. Constructing the independent variable
a. The independent variable is the experimental manipulation.
b. Manipulation checks provide information about the extent to which the experimental
treatment had its intended effect on each individual participant.
c. Manipulate the independent variable on a between-subject or within-subject basis
i. Between-subject design à people are randomly assigned to different levels of
the independent variable
ii. Within-subject design à all participants receive all levels of the independent
variable
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, 1. This is often preferred, because fewer participants are required to
achieve sufficient statistical power: each participant serves as his or
her own control; each person’s responses in one condition are
compared to that same person’s responses in the other conditions.
2. It is important of course to vary the order of the experimental
conditions to make sure that the effects of the independent variable
are not confounded with the order in which people receive the
different manipulations (counterbalancing).
3. However, although preferable, they are often times not feasible.
d. Demand characteristics à form of participant awareness bias and refers to features
introduced into research setting by virtue of the facts that it is a research study and
that the participants know that they are part of it.
i. Most effective type of deception is presenting the independent variable as an
event that appears not to be part of the experiment at all: “accident” or
“whoops” manipulation: in which the independent variable is presented as
part of what appears to be an accident or unforeseen circumstance.
3. Measuring the dependent variable
a. Decide whether to rely on participants’ self-reports or observations by others as the
means of assessing a person’s responses to the experimental situation.
4. Planning the post-experimental follow-up
a. To ensure that the participants are in a good and healthy frame of mind.
b. To be certain that the participants understand the experimental procedures, the
hypotheses, and their own performance so that they gain a valuable educational
experience as a result of having participated.
c. To avail themselves of the participants’ unique skill as a valuable consultant in the
research enterprise.
d. To probe for any suspicion on the part of the participants, such as whether they
believed the cover story.
e. It is important to first explore (gently and gradually) with each the impact of the
experimental events, before providing a complete understanding!
f. A thorough explanation of the experiment should always be provided (whether or not
deception is used or stressful procedures are involved).
Moving into the field – Advantage of laboratory experiment is that the researcher has more
control over the situation, which allows for a cleaner manipulation of the IV.
In field experiments it is more likely that unforeseen, uncontrolled events will occur that will
compromise the integrity of the experimental design. But advantages:
• People are less likely to know that they are in an experiment.
• The setting will be more like once people encounter in their everyday lives.
Control over the Independent Variable in field settings:
• The field version of the basic research paradigm cannot be simply a transplanted
replication of the laboratory operations: less control in field setting; no control over
implementation of stimulus conditions or extraneous sources of variation
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, • Results of field experiment as a single isolated study would be difficult to interpret
without the context of conceptually related laboratory experiments.
Random assignment in field settings:
• Self-selection to experimental conditions is not random assignment
• Burden of proof rests on the investigator to make a convincing case that the groups
are not likely to differ systematically in any relevant dimensions other than the causal
event of interest.
Assessment of Dependent Variables in field settings
• Parallel to that of laboratory settings
• Advantage of experimentation in field settings is the potential for assessing behaviors
that are in and of themselves of some significance to the participant.
• Reactivity à the possibility that the measurement of the dependent variable reacts
with the independent variable or related events in such a way that effects are found
that would not have been present otherwise.
Validity and realism in experiments:
• Experimentation almost always involves a trade-off between competing goals: control
and realism.
• Internal validity à well-controlled; random assignment)
• External validity à generalizable to other settings and people)
• Construct validity à independent and dependent variables reflect the conceptual
variables of interest.
• Mundane realism à the extent to which events occurring in the research setting are
likely to occur in the normal course of the participants’ lives, that is, in the real world.
• Experimental realism à situation is involving to the participants, participants are
forces to take experiment seriously, experiment has impact on them.
• Mundane realism and experimental realism are not polar concepts.
• Psychological realism à extent to which the psychological processes that occur in an
experiment are the same as psychological processes that occur in everyday life.
• Ethical concerns à Informed consent is important.
1-2 When Choice is Demotivating: Can One Desire Too Much of a Good Thing?
Iyengar & Lepper (2000)
Popular notion: the more choice, the better – that the human ability to manage, and the
human desire for, choice is unlimited. However, findings from 3 experimental studies starkly
challenge this implicit assumption that having more choices is necessarily more intrinsically
motivating than having fewer. These experiments (both field and laboratory) show that
people are more likely to purchase gourmet jams or cholates or to undertake optional class
essay assignments when offered a limited array of 6 choices rather than a more extensive
array of 24 or 30 choices. Moreover, participants actually reported greater subsequent
satisfaction with their selections and wrote better essays when tier original set of options had
been limited.
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