CHAPTER 10 + 11 Flashcards
What is an Independent Variable?
controlled by researcher
what is Dependent Variable?
variable measured
What is Control Variable?
variable held constant
What is the DV and IV: A psychologist is studying the impact of sleep duration on mood. Participants are randomly assigned to one of three groups: Group A (4 hours of sleep), Group B (8 hours of sleep), and Group C (12 hours of sleep). After one week, participants rate their overall mood on a scale from 1 to 10.
DV: MOOD IV: HOURS OF SLEEP
What is a true experiment?
Independent variables are controlled
by the researcher where PPS are randomly assigned to groups
What is a Quasi-Experiment?
Comparison groups are not formed
by the researcher and therefore are not under the
control of the researcher, random assignment not always possible or ethical (male/female)
What can you expect if you randomly assign participants to groups?
individual differences are evenly
spread out across conditions
What is Covariance?
causal variable related to
the effect variable, needs comparison group, includes two IV’S (compare and control)
How do Experiments Support Causal Claims?
Covariance/Temporal Precedence/Internal Validity
Internal Validity
results from our manipulation
what is Extraneous variables?
additional factors in a research study that are not the main variables under investigation
what is a confounding variable?
extraneous factors that consistently vary alongside the independent variable in a research study.
what is selection effect
difference in characteristics or qualities in PPS being compared
what is a design confound?
mistake in designing study
How to avoid confounding variables?
Keep things constant, random assignment
4 ways to Carry out an Experiment with Participants
Independent groups design/Within-groups design/Matched Groups Design/Mixed Design
what is Independent Groups Design?
Participants only take part in only one condition of the experiment
what is Within-Groups Design?
Participants take part in all conditions
(repeated measures or concurrent measures)
Advantages of Within-Participants Design
Less concern over individual differences/fewer participants
Disadvantages of within-groups design
Practice Effects/Fatigue or Boredom/Carryover Effects/need to counterbalance
what is Matched Groups Design
Participants are matched in each condition for characteristics that
may have an effect on their performance/reaction
what is Mixed Design
looks at one or more things between different groups of people (like giving them different treatments), and at the same time, it looks at something within the same people (like measuring their performance multiple times)
Alex is wondering how a training class
for expectant mothers affects their
confidence in caring for their new baby
once they have given birth. What kind
of design might Alex use to research
this topic? Is there anything Alex should
be careful about when using this
design?
Matched, based on experience.age.support
In an experimental study on gender bias in hiring, after being
presented with the stimulus materials, participants were able to
determine the purpose of the study. This problem is an
example of
demand characteristic
A friend of yours, a senior, took the Graduate Record Exam in
September and scored in the 99th percentile. In February, your
friend took the same exam over again. This time your friend
scored in the 84th percentile. As a research methods student,
you told your friend that his/her lowered score was most likely
due to
Statistical regression
A researcher pretests a group of participants to determine
their attitudes toward the use of alternative energy sources to
replace crude oil. The researcher then initiates a program to
convince them that they should invest in such alternatives.
During this time, the price of gasoline rises $.50 per gallon. At
the end of the program, the researcher retests and finds that
the participants are much more positive in their attitudes. What
threat to internal validity most likely accounts for this change?
History
