Chapter 5 Flashcards
conditions
The different levels of the independent variable to which participants are assigned
control
Holding extraneous variables constant in order to separate the effect of the independent variable from the effect of the extraneous variables.
extraneous variables
Any variable other than the dependent and independent variable.
single factor two-level design.
An experiment design involving a single independent variable with two conditions.
single factor multi level design
When an experiment has one independent variable that is manipulated to produce more than two conditions.
Extraneous Variables as “Noise”
Data can be all over the place based on factors outside the independent elements that influence the control elements. mood can be such a thing. It’s important to limit this as much as possible for better data
Ways to control Extraneous variables
to hold them constant
holding participant variables constant.
confounding variable
An extraneous variable that varies systematically with the independent variable, and thus confuses the effect of the independent variable with the effect of the extraneous one.
Difference between extraneous and confounding variables
An extraneous variable is any variable that you’re not investigating that can potentially affect the dependent variable of your research study.
A confounding variable is a type of extraneous variable that not only affects the dependent variable, but is also related to the independent variable.
treatment
Any intervention meant to change people’s behavior for the better.
treatment condition
The condition in which participants receive the treatment.
control condition
The condition in which participants do not receive the treatment.
randomized clinical trial.
An experiment that researches the effectiveness of psychotherapies and medical treatments.
no-treatment control condition
The condition in which participants receive no treatment whatsoever.
placebo control condition
Condition in which the participants receive a placebo rather than the treatment.
In these experiments. They hold a no condition, placebo condition and treatment condition and measure the effectiveness by measuring the difference between the treatment and placebo conditions
wait-list control condition
Condition in which participants are told that they will receive the treatment but must wait until the participants in the treatment condition have already received it.
Sham surgery example
When people got a false surgery and experienced improvement in knee pain even though nothing happened
An experimenter conducts a study with three different conditions. The experimenter ensures that participants engage in every condition of the experiment. The experimenter is using a:
A. Between-Subjects design
B. Within subjects design
C. Matched-Subjects design
D. Temporal Order design
B. Within subjects design
A confounding variable is a threat to establishing causality because it _________, so it is impossible to determine which variable caused the dependent variable to change.
A. Does not covary with the independent variable
B. Dose not covary with the dependent variable.
C. Covaries with the independent variable
D. Covaries with the dependent variable
C. Covaries with the independent variable
Random assignment ensures that participants:
A. Are assigned to certain experimental conditions based on the participants individual preferences
B. Are assigned to certain experimental conditions based on individual differences observed by the experimenter
C. Have an equal probability of being assigned to any of the experimental conditions.
D. Are all treated in the same way during the experiment
C. Have an equal probability of being assigned to any of the experimental conditions.
Counterbalancing is particularly important in a:
A. Between-subjects design
B. Within-subjects design
C. Matched groups
D. Non-experimental
B. Within-subjects design
between-subjects experiment
An experiment in which each participant is tested in only one condition.
random assignment
Means using a random process to decide which participants are tested in which conditions.
Does have some issues like chance errors or chance extraneous/confounding variables
Conditions for random sampling
One is that each participant has an equal chance of being assigned to each condition
The second is that each participant is assigned to a condition independently of other participants.
block randomization.
All the conditions occur once in the sequence before any of them are repeated.
This is done via computer and a way to ensure random sampling without having the groups being different sizes according to chance
matched-groups design.
An experiment design in which the participants in the various conditions are matched on the dependent variable or on some extraneous variable(s) prior the manipulation of the independent variable.
its a way of factoring in known extraneous variables such as psychological health
within-subjects experiment
An experiment in which each participant is tested under all conditions
it is useful because it provides maximum control over extraneous variables however not all experiments benefit from this. The order effect is such a disadvantage
order effect
A disadvantage to within-subjects experiments where the effect that occurs when participants’ responses in the various conditions are affected by the order of conditions to which they were exposed.
carryover effect
A type of order where the effect of being tested in one condition on participants’ behavior in later conditions
practice effect
A type of carryover effect where participants perform a task better in later conditions because they have had a chance to practice it.
Fatigue effect
Another type of carryover effect where participants perform a task worse in later conditions because they become tired or bored.
context effect (or contrast effect).
Unintended influences (such as the experiment changing perceived stimuli) on respondents’ answers because they are not related to the content of the item but to the context in which the item appears.
Such as jurors judging ugly defendants more harshly
Counterbalancing
Varying the order of the conditions in which participants are tested, to help solve the problem of order effects in within-subjects experiments.
complete counterbalancing
A method in which an equal number of participants complete each possible order of conditions
random counterbalancing
A method in which the order of the conditions is randomly determined for each participant.
This is not as powerful a technique as complete counterbalancing or partial counterbalancing using a Latin squares design. Use of random counterbalancing will result in more random error
When 9 Is “Larger” Than 221 example
Participants in this between-subjects design gave the number 9 a mean rating of 5.13 and the number 221 a mean rating of 3.10. In other words, they rated 9 as larger than 221! According to Birnbaum, this difference is because participants spontaneously compared 9 with other one-digit numbers (in which case it is relatively large) and compared 221 with other three-digit numbers (in which case it is relatively small).
Simultaneous Within-Subjects Designs
When people make multiple responses in a single condition such as rating the attractiveness and unattractiveness of two groups at the same time
Pros and cons of Between-subjects and within-subjects experiments
Advantages of Between subjects:
-conceptually simpler and requiring less testing time per participant.
-They also avoid carryover effects
Within-subjects experiments advantages
-have the advantage of controlling extraneous participant variables, which generally reduces noise in the data
Within-subjects experiments also require fewer participants than between-subjects experiments to detect an effect of the same size.
Which is better typically, Between-Subjects or Within-Subjects?
Within-subjects.
A researcher conducts an experiment with 100 children. Different Children are assigned to each of the conditions of the experiment. The experiment is an example of a:
A. Child-centered experiment
B. Random-subject design
C. Between Subjects Design
D. Within-subjects design
C. Between Subjects Design
A researcher conducts a study examining the alcohol consumption of male and female college students. She brings the male students into the laboratory the week before spring break. She brings the female students into he laboratory the week after spring break. if the researcher is interested in the influence of gender, then the difference in timing of the two groups may be a(n):
A. independent variable
B. Dependent variable
C. Between Subjects Design
D. Extraneous variable
C. Between Subjects Design
Two researchers were studying the effects of intelligence on coping strategies. One of the researchers was concerned that her measure of intelligence (grade point average in high school) might not accurately represent intelligence. the researcher is concerned about_________?
A. Internal Validity
B External Validity
C. Statistical Validity
D. Construct Validity
B External Validity
internal validity
Refers to the degree to which we can confidently infer a causal relationship between variables.
The way an empirical study is conducted and the manipulation of the variable minimizes extraneous variables can create higher external validity
external validity
Refers to the degree to which we can generalize the findings to other circumstances or settings, like the real-world environment.
mundane realism
When the participants and the situation studied are similar to those that the researchers want to generalize to and participants encounter every day.
basically the experiment replicates real life pretty well
Psychological realism
Where the same mental process is used in both the laboratory and in the real world.
Construct validity
One of the “big four” validities, whereby the research question is clearly operationalized by the study’s methods.
the quality of the experiment’s manipulations
operationalization
The specification of exactly how the research question will be studied in the experiment design.
Statistical validity
Concerns the proper statistical treatment of data and the soundness of the researchers’ statistical conclusions.
such as t-tests, ANOVA, etc.
Subject pool
An established group of people who have agreed to be contacted about participating in research studies.
experimenter expectancy effect
When the experimenter’s expectations about how participants “should” behave in the experiment affect how the participants behave.
Such as the maze-bright and maze-dull examples with rats. There was no difference in the rats but the experimenters reported there was due to this effect
manipulation check
Verifying the experimental manipulation worked by using a different measure of the construct the researcher is trying to manipulate.
Pilot test
Is a small-scale study conducted to make sure that a new procedure works as planned.
A researcher designs a study whose procedures and setting resemble a classroom setting. The researcher is confident that the results of the study will closely approximate what will be a real-world regarding the relationship between the independent and dependent variables. He believes the study is high in______________.
A. Internal Validity
B. External Validity
C. Statistical validity
D. Construct Validity
B. External Validity
In a single-blind study_____________does not know if a placebo or treatment was administered. In a double-blind study _____________does not know if a treatment or placebo was administered.
A. The Participant; the researcher
B. The researcher; the participant
C. The participant; the researcher and the participant
D. The researcher; The participant and the researcher
C. The participant; the researcher and the participant
