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Other single subject designs part 2. Another design is the A-B-A design. An A-B-A design (also known as a reversal design) involves discontinuing the.

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Presentation on theme: "Other single subject designs part 2. Another design is the A-B-A design. An A-B-A design (also known as a reversal design) involves discontinuing the."— Presentation transcript:

1 Other single subject designs part 2

2 Another design is the A-B-A design. An A-B-A design (also known as a reversal design) involves discontinuing the intervention and returning to a baseline. Frequency of disruptions Day 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 876543210876543210 Baseline Praise Baseline

3 Another design is the A-B-A design. An A-B-A design (also known as a reversal design) involves discontinuing the intervention and returning to a baseline. Frequency of disruptions Day 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 876543210876543210 Baseline Praise Baseline A B A

4 Of course in these designs where you withdraw treatment (sometimes called reversal designs), you always restore treatment For example, an A-B-A-B design

5 HERE IS WHAT A COMPLETE A-B-A-B CHART MIGHT LOOK LIKE Notice that there is no use of statistics here. One can see the effects of the intervention. By withdrawing the intervention, we can see empirically (through the senses), that the intervention is the cause of the change. We use statistics when we cannot directly see the results or when we can’t Trust our senses

6 But why would you withdraw treatment? Recall that “evidence-based practice” requires that you show that it is the treatment or intervention that is producing the change. By removing the treatment and reintroducing it – an A-B-A-B design, we establish a causal link between the problem behavior and the intervention

7 But what else could cause the change in the problem behavior? –Perhaps the stressor that causes the problem just goes away –Sometimes people just naturally change over time –Sometimes just the act of measuring a problem decreases its occurrence. ( a good example is how ‘calorie counting’ is used in ‘weight watchers’.) In research, these are known as threats to internal validity. What that means simply is that other things could be causing the change and not your intervention so the experiment is invalid. you have no proof that the intervention is causing the change.

8 EXPERIMENTAL CONTROL Single-subject research designs provide experimental control for most threats to internal validity and, thereby, allow confirniiuion of a functional relationship between manipulation of the independent variable and change in the dependent variable. In most cases experimental control is demonstrated when the design documents three demonstrations of the experimental effect at three different points in time with a single participant (within-subject replication), or across different participants (inter-subject replication). An experimental effect is demonstrated when predicted change in the dependent variable covaries with manipulation of the independent variable (e.g., the level, and/or variability of the dataset in a phase decreases when a behavior-reduction intervention is implemented, or the level and/or variability of the dataset in A phase increases when the behavior-reduction intervention is withdrawn). Documentation of experimental control is achieved through (a) the introduction and withdrawal (or reversal) ot the independent variable; (b) the staggered introduction of the independent variable at different points in time (e.g., multiple baseline); or (c) the iterative manipulation ol^ the independent variable (or levels of the independent variable) across observation periods (e.g., alternating treatments designs).

9 But isn’t it UNETHICAL to withhold or withdraw treatment? We will deal with this later in the presentation! But what if the behavior is so severe that treatment or intervention is needed immediately?

10 Sometimes an individual’s behavior is so severe that the researcher cannot wait to establish a baseline and must begin with an intervention. In this case, a B-A-B design is used. The intervention Frequency of disruptions Day 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 876543210876543210 Praise

11 Sometimes an individual’s behavior is so severe that the researcher cannot wait to establish a baseline and must begin with an intervention. In this case, a B-A-B design is used. The intervention is followed by a baseline Frequency of disruptions Day 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 876543210876543210 Praise Baseline

12 Sometimes an individual’s behavior is so severe that the researcher cannot wait to establish a baseline and must begin with an intervention. In this case, a B-A-B design is used. The intervention is followed by a baseline followed by the intervention. Frequency of disruptions Day 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 876543210876543210 Praise Baseline Praise Notice that treatment is withdrawn for only a brief time period!

13 Sometimes an individual’s behavior is so severe that the researcher cannot wait to establish a baseline and must begin with an intervention. In this case, a B-A-B design is used. The intervention is followed by a baseline followed by the intervention. Notice that treatment is withdrawn for only a brief time period! Frequency of disruptions Day 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 876543210876543210 Praise Baseline Praise B A B

14 Another alternative to a B-A-B design is THE RECONSTRUCTED BASELINE A reconstructed baseline is a baseline that is created by the client’s recollection of the problem or problem behavior. Here you do not directly measure the client’s problem, but measure indirectly through the client (or parents or teachers etc) self-report of what the problem was like before they came to you.

15 This can be done through a thorough assessment (how does the client DO the problem?) when meeting with the client. A reconstructed baseline has the same dimensions as a direct baseline measurement. It is: –Thorough –Specific (frequency, duration or magnitude) –Measurable (quantifiable) –observable –Valid – it measures the problem and what you are trying to change –Sensitive to changes –individualized Many practitioners use a reconstructed baseline

16 Frequency of disruptions Day 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 876543210876543210 Baseline Praise Condition change line Data points Data path Measure of time Unit of time Dependent measure Condition identificationsIndependent variable Regardless of the research design, the line graphs used to illustrate the data contain a set of common elements.

17 Frequency of disruptions Day 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 876543210876543210 Baseline Praise Condition change line Data points Data path Measure of time Unit of time Dependent measure problem Condition identificationsIndependent variable intervention Regardless of the research design, the line graphs used to illustrate the data contain a set of common elements. Please read Chapter 14 in your text to learn more about Single-Subject Research and other Single-Subject Research Designs.

18 BUT ISN’T IT UNETHICAL (AND CRUEL) TO WITHDRAW TREATMENT? Most of the time, it is! It is not, when the problem is not debilitating Or when withdrawing treatment helps the client SEE the importance of continuing treatment ARE THERE ALTERNATIVES TO WITHDRAWING TREATMENT? YES!

19 AN A-B-C RESEARCH DESIGN “A” PHASE = BASELINE “B” PHASE = INTERVENTION OR TREATMENT. (NOTICE THAT SO FAR NOTHING IS DIFFERENT) “C” PHASE = 1. EITHER A LESSENING OF THE INTERVENTION (RECALL THE EXAMPLE OF PRAISE AS AN INTERVENTION. HERE ‘PRAISE’ WOULD BE LESSENED TO ‘GIVING PRAISE’ AT THE END OF ONE CLASS PERIOD RATHER THAN EVERY TIME THE CHILD DOES SOMETHING RIGHT ) OR 2. ADDING ANOTHER INTERVENTION OR TREATMENT COMPONENT IN ADDITION TO THE ONE YOU ARE ALREADY USING IN THE “B” PHASE.

20 MULTIPLE BASELINE RESEARCH DESIGNS Multiple baseline designs involve 2 or more participants, two or more settings that the problem occurs in or two or more problem behaviors Does not require a reversal or withdrawal Relies on staggered implementation of intervention to demonstrate cause-effect Participants’ behavior should change only when the intervention is introduced

21 Multiple baseline with different subjects

22 At the very least, you should be able to use a simple A-B design Baseline A Treatment B Eye Contact Time in Weeks Above is an example of a design working with someone who has a “social phobia’ or shyness. Notice that we are working only with one problem Component of shyness; “eye contact”

23 Baseline A Treatment B Making small talk Time in Weeks Above is an example of a design working with someone who has a “social phobia’ or shyness. Notice that we are working only with one problem Component of shyness; “making small talk” after the client can establish some eye contact. YOU DO NOT HAVE TO WAIT UNTIL THE FIRST PROBLEM BEHAVIOR IS SOLVED TO BEGIN THE SECOND INTERVENTION; JUST MAKE SURE IT IS IMPROVING However, we could turn this into a ‘multiple baseline’ by adding another “problem behavior” that is a component of shyness AFTER AND ONLY AFTER eye contact has shown some improvement (MAYBE THE THIRD WEEK OF TX)

24 Baseline A Treatment B GOING OUT WITH FRIENDS Time in Weeks Thus in 5 or 6 sessions, we have begun to treat and measure three changes in problem behaviors that are components of Shyness. With a multiple baseline, we treat begin the treatment of problem behaviors, one at a time. In the 5 th session we could add another “problem behavior” that is a component of shyness; going out with friends

25 One can also use a multiple baseline with different clients, rather than the problem behaviors of a single client Or the problem behavior of one client in different settings. For example,with a child who mis-behaves ‘everywhere’, we might first focus on behavior at school, then the same behavior at home, then the same behavior in social situations. The important thing is that the baselines and interventions are ‘staggered’ to show a ‘causal relationship between the dependent variable (the problem) and the independent variable (the treatment)

26 Multiple baseline N O T I C E How Tx Is S T A G E R E d Or problem #1 Or problem #2 Or problem #3


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