Unit 7

Question 1

Compare the assumptions between the single subject approach and the individual differences group research approach to psychological research

Answer 1

A traditional assumption of researchers doing single subject experience has been that individual participants are essentially equivalent and that one should study additional participants only to make sure the original participant was not grossly abnormal. The single participant traditional seems that most variability in the participants behavior is imposed by the situation and therefore can be removed by careful attention to experimental control. The individual differences, group research tradition assumes that much of the variability is intrinsic and should be statistically controlled and analyzed

Question 2

What are the advantages of the single subject approach?

Answer 2

It focuses on an examination of behavior change and one person which allows for an intensive study of the individual client and experimental evaluation of treatment for that particular client. Individual subjects act as their own control which avoids the possibility that the average picture is a distortion of the behavior of the individual participants

It requires only a small number of subjects especially where experimental subjects are difficult to find, for instance patients with damage in a particular part of the brain.

Withholding a potentially beneficial treatment from some patients is not required in order to provide a control group

In a single participant experiment, the effect of a minor variable is less likely to be discovered so the experimenter will not be distracted by it and the research you can then spend time reducing variability so that the effect of a given variable will be maximized, instead of spending time testing more participants

Question 3

What are some disadvantages of the single subject approach?

Answer 3

Some effects are small relative to the amount of variability in the situation. It may be impossible to control the other sources of variability sufficiently to observe the experimental effect in one subject. Some experimental effects are by definition between subject effects

Question 4

The measure of behavior before treatment that establishes a reference point for evaluating the effect of treatment

Answer 4

Baseline

Question 5

A type of single subject research, also called the comparison design; single participant research design that consists of a baseline followed by a treatment

Answer 5

AB design

Question 6

A single subject research design that includes a baseline period, a treatment period, and a subsequent withdrawal of treatment

Answer 6

ABA design

Question 7

What two principal problems are associated with the ABA design

Answer 7

The effect of the manipulation may not be fully reversible. You may want to leave the participants in the new condition rather than return them to their original state

Question 8

A single subject research design, also called the repeated treatments or replication design; an ABA design with treatment repeated after the withdrawal phase

Answer 8

ABAB design

Question 9

When is the a B a B design superior to the ABA design?

Answer 9

The participant is left with the full benefit of the treatment and the repetition of treatment also has the advantage of providing another opportunity to evaluate the effect of the treatment and its reliability.

Question 10

A type of single participant design that allows the comparison of two different independent variables

Answer 10

Alternating treatments design

Question 11

Research design that introduces different experimental manipulation’s to see if changes coincide with manipulation. Three types of manipulation: behaviors, subjects, and settings

Answer 11

Multiple-baseline design. Especially useful if the expected behavior changes irreversible, because you don’t have to remove the treatment to demonstrate causality. Each untreated situation acts as a second baseline for the treatment conditions

Question 12

Name several prominent psychologist in history who used single subjects in psychological research

Answer 12

Gustav Fechtner in psychophysics, Herman Ebbinghaus in memory, and Pavlov in conditioning of individual dogs

Question 13

Designed that measures the effects of implementing a treatment following baseline measurement to multiple behaviors in the same subject sequentially, so that each untreated behaviors baseline acts as a control for those that have been treated

Answer 13

Multiple-baseline across behaviors

Question 14

Designed that measures the effects of implementing a treatment following baseline measurement to multiple subjects sequentially, so that each untreated subjects baseline acts as a control for those that have been treated

Answer 14

Multiple-baseline across subjects

Question 15

Designed that measures the effects of implementing a treatment following a baseline measurement of the subjects behavior in multiple settings sequentially, so that each untreated settings baseline acts as a control for those that have been treated

Answer 15

Multiple-baseline across settings

Question 16

Research design that introduces successively more stringent criteria for reinforcement to see if behavior change coincides with the changing criteria

Answer 16

Changing-criterion design

change the criterion for reward overtime. After baseline measurement, a reward can be given for meeting a lax criteria of behavior. After the behavior stabilize that that level, the criterion can be raised until the behavior stabilizes again, and so forth. If the behavior begins to change after each change in the criterion, then the conclusion that the reward is the cause of the improvement is rather convincing. For instance, rewarding a child for sitting still for five minutes at a time until the performance become stable.

Question 17

Describe two areas of psychology in which the single subject approach is commonly used

Answer 17

Visual thresholds in humans. For instance, an experiment measured the threshold for the detection of a flash of colored lights seen against the background of a different color. They were interested in whether the color of the background made any difference threshold for the flashing their situation

Visual threshold and pigeons. An experiment studied the dark adaptation curve of the pigeon. The researchers train to pigeon to perform one task to have a chance to perform a second one that will lead to food being able to form the second task becomes a reinforcer for performing the first one. The birds would peck the first key to drive the light so low that they cannot see it, which signals them that they are then able to peck the second one for food. To make sure the pigeon wasn’t simply pecking a while at the first key and then switching to the second key even though they could still see the light, the researchers would every so often have pecking the first key cause like to go completely dark and only at such times was pecking on the second key reinforced. Therefore, Blau was sure that the pigeon switched to the second key only when it could not see the light