Ch.11 Correlated-Groups and Single-Subject Designs
What are the 3 conditions in the target search study?
1) 10 distractors 2)15 distractors 3) 20 distractors
What are the strengths of Within-Subjects Design?
1) More sensitive to small group differences. 2) Fewer participants are needed. 3) Instructions may take less time.
When does matching participants get more difficult?
1) The number of matching variables increases. 2) Matching is done on continuous variables. 3) The number of conditions increases.
What are relevant variables of Matched-Subjects Design?
1) Variables that affect the dependent variable. 2) Variables that show considerable natural variation in the population sampled.
What are the 3 variants of single-subject experimental design?
1)ABA Reversal design 2)Multiple baseline designs 3)Single-subject, randomized, time-series design
How does ABA Reversal design work?
1)Apply then remove, independent variable manipulation. 2)If change occurs at both application and removal, it suggests a causal connection.
What are the weaknesses of Within-Subjects Design?
1)Because participants experience all conditions, they may figure out the hypothesis. 2)Major issue is sequence effects.
What are the controls of sequence effects?
1)Control PPE with prior training 2)Control NPE with rest intervals 3)Control carryover effects by varying the order of conditions
What are the characteristics of within-subjects design?
1)Each participant is tested under each experimental condition. 2)Therefore, the scores in each condition are correlated with the scores in the other conditions. 3)The critical comparison is the difference between correlated groups on the dependent variable.
Why is it logical to use single subject designs?
1)Includes independent variable manipulation 2)Expect dependent variable response 3)Multiple measures before and after the manipulation to identify normal variation and rule out regression to the mean.
What are the sources of sequence effects?
1)Positive Practice Effects (PPE) 2)Negative Practice Effects (NPE) 3)Carryover Effects
What is the procedure of the single-subject, randomized time-series design?
1)Select minimum baseline and follow-up periods 2)Randomly select the point of intervention 3)Compare pattern of scores before and after the intervention
What are the 2 ways to control sequence effects?
1)holding the extraneous variable constant 2)varying the order of presentation of conditions
What is the procedure for Multiple Baseline Designs?
1.Baseline 2.Manipulation focused on first dependent variable 3.Manipulation focused on second dependent variable
How many orders of presentation are necessary to counterbalance in an experiment with four experimental conditions?
24
What does the A and B stand for in the AB design?
A=Baseline B=Intervention
Reversal designs are also called
ABA designs
Which design looks at when the treatment is applied and then removed?
ABA reversal design
What are the types of ABA design?
ABA reversal design and ABAB design
What are the variations on Multiple Baseline Designs?
Across behaviors, across individuals, and across settings and time
What happens Within-Subjects Designs?
All participants are exposed to all experimental conditions.
Why are sequence effects a major issue within-subjects designs?
Because of practice and carry-over effects
Why do do the instructions take less time in within-subject designs?
Because the participants were already instructed on the task in previous conditions.
Why is an ex post facto, single case study weak?
Because the researcher does not control the independent variable.
The single-subject, randomized, time-series design
Both 2 and 3
The clinical researcher must not only see that no harm comes to the participants, but has the added ethical responsiblility to do what?
Bring about some positive gain for the participants.
How are sequence effects controlled?
By counterbalancing
How are factorials calculated?
By multiplying the number by all intergers smaller than the number. Example: (X!=3x2x1=6)
When all possible orders of conditions occur an equal number of times it is called?
Complete counterbalancing
What is the procedure for ABA reversal design?
Condition A-Baseline measures Conditon B-Treatment application Conditon A- Baseline again
What is the difference between direct replication and systematic replication?
Direct replication repeats the study on the same target behavior and systematic replication evaluates procedures across subjects, settings, and/or target behaviors.
Which of the following is true for within-subjects designs?
Each participant serves as his or her own control.
True/False: We can confidently make the claim that in single-subject design the variation in independent variable did not cause the changes in dependent variable or measure.
False- I did cause the changes in dependent variable or measure.
True/False: Counterbalancing is very effective with a large number of conditions.
False- It is effective with a small number.
True/False: The critical comparison in the matched-subjects designs is the difference between the subject groups, in which the matching procedures creates the condition.
False-It is the difference between the correlated groups, and it creates the correlation.
What is a concern of single-subject design?
Generalizability or external validity
What is different about clinical replication?
It combines procedures into a treatement "package".
What is the major strength of the within-subjects design?
It guarantees that the participants in the various conditions are equivalent at the start of the study.
Which design introduces correlation through matched random assignment?
Matched-Subjects Design
Within-subjects design is also known as?
Repeated measures design
What does the single-subject, randomized time-series design do?
Repeated measures of the dependent variable interupped by a randomly placed intervention.
What does Multiple Baseline Designs do?
Shows the effect of the independent variable on several dependent variables.
What design is an extension of within-subjects design?
Single-Subject Design
In within-subjects designs, the removal of individual differences would have what effect on the F-ratio?
The F will be larger.
When matching participants how many participants do you need in your sets?
The set size is equal to the number of conditions.
How does a single-subject design work?
The single participant is tested under all conditions, with the researcher actively manipulating the independent variable.
What is an advantage of the matched-subjects design over the within-subjects design?
There are no problems of practice and carryover effects.
Which of the following is true about single-subject designs?
They are variations of within-subjects designs.
Why do the authors of this text consider correlated-groups designs to be true experiments?
They meet the requirement of equivalence of groups.
What makes within-subjects designs more sensitive than between-subjects designs?
They reduce error variance.
True/False: If change occurs at the point of intervention, it suggests a causal connection.
True
True/False: Matched-Subjects Design should match on "relevant" variables.
True
True/False: Positive practice effects can be controlled by holding the practice variable constant.
True
True/False: Well thought single-subject design has good internal validity.
True
True/False:In within-subjects designs, each participant serves as his or her own control.
True
When do you use multiple baseline designs?
When reversals are undesireable and behavioral changes would not reverse.
When are matched subjects designs likely to be used?
When the cost per participant is very high.
Which design has the same participants in each group?
Within-subject designs
How do experimental designs introduce a correlation between groups?
Within-subject designs and matched-group designs
What is known as testing effects on different behaviors?
across behaviors
What is known as testing effects on different people?
across individuals
What is known as testing effects in different settings or at different times?
across settings
Replication can be achieved in single-subject designs through
all of the above
Compared with between-subjects designs, correlated-groups designs
are more sensitive to the effects of the independent variable.
Single-subject designs
are usually variations on time-series designs.
Why is a final A to B (i.e., back to the treatment) reversal sometimes carried out in reversal designs?
both a and c
Effects that are due to the influence of a particular condition on responses to conditions that follow are called
carry-over effects.
In within-subjects designs, the unwanted effects due to the influence of one condition on the following conditions is called
carry-over effects.
What are the 2 statistical analysis that you can use for within-subject designs?
correlated t-test (for 2 groups only); and repeated measures ANOVA
When the order of presentation of conditions to participants is systematically varied it is called?
counterbalancing
Which of the following is a major control for sequence effects?
counterbalancing
Single-subject experiments
differ from case studies because independent variables are manipulated.
In matched-subjects designs,
each participant is exposed to only one level of the independent variable.
In randomized, between-subjects experimental designs, each participant is
exposed to only one level of the independent variable.
A target search study is a ___________.
hypothetical study
Matching participants
is best when there are a small number of matching variables.
When does treatment begin in a single-subject, randomized time-series design?
it is determined randomly
The key to analyzing data from a matched-subjects designed is to
maintaining the information on the matching of participants all away through to the analyses.
A researcher is using a within-subjects design. After condition two (there are a total of three conditions), the researcher notices that the participants are looking bored and restless. After the third condition, the researcher records a falling off of performance. This is a(n)
negative practice effect.
What is the first step to analyzing the results of within-subjects designs?
organize and summarize the data
What is the term for the unwanted enhancement of performance on subsequent conditions in within-subjects designs?
positive practice effect
What are the two most important sequence effects?
practice effects and carryover effects
Which of the following is NOT used in correlated-groups designs?
random assignment to conditions
Once sets are matched, _________ participants in the set to the conditions.
randomly assign
Which of the following is an appropriate statistical test for a within-subjects experiment with two experimental conditions and a dependent variable that produces score data?
repeated measures ANOVA
The appropriate ANOVA for a within-subjects design is called?
repeated-measures ANOVA
Which of the following is a potential confounding factor in within-subjects designs, but not in a between-subjects design?
sequence effects
A potential confounding factor that can occur in within-subjects designs if the researcher does not vary the order of presentation is called
sequence effects.
Matching participants on the variable of sex is relatively simple because
sex of participants has only two levels.
In the repeated-measures ANOVA, the within-groups sum of squares is split into the _____ and the _____.
subjects term; error term
Counterbalancing involves ______ arranging the order of conditions so that _____ possible _____ are represented the ______ number of times.
systematically, all, orders, same
What did Skinner advocate for?
the ANOVA test
In ABA reversal designs, the effects of the independent variable on the dependent variable are demonstrated if
the behavior changes in the predicted direction whenever the conditions are reversed.
Correlated-groups designs are generally more sensitive than between-subjects designs to
the effects of the independent variable.
The "experimental analysis of behavior" refers to the development of methods for
the intensive, systematic, and controlled study of individual participants.
A within-subjects design helps to ensure the equivalence of groups at the start of the experiment because
the participants in one group are the same participants as in the other groups.
If strong carry-over effects are expected in an experiment,
the within-subjects design is not recommended.
A target search study contains what 3 things?
within-subject design, six participants, and the three conditions
In which design are all participants exposed to all experimental conditions?
within-subjects
What are the two types of designs used to introduce the correlation in correlated-groups designs?
within-subjects designs and matched-subjects designs
