PSYC 164

Graphing Behaviour and Measuring Change

 In behavioural research, we must show two things in order to determine the research’s scientific validity: ▪ That the treatment phase did, in fact, change behaviour

▪ That the results can be replicated (that is, we can use the same treatment, with the same procedure and get similar results)

 Keep this in mind as we look at different research designs.

 In behavioural research, as explained in the graphing section of the introduction, a single subject’s data is divided into baseline (before treatment) and treatment (once intervention has begun).

 On a graph, the researcher will either write the words “baseline” and “treatment” above the phase, or they will denote them using

▪ A = baseline

▪ B = treatment

 A-B Design

 This research design has one baseline phase followed by a treatment phase. For example:

 This is a popular design in the applied field because it allows a simple comparison between before and after treatment. It is simple and that is an advantage. It is often used when we just care that we made a change and we’re not worried about the effects of other variables.

 Looking at the two conditions we must meet to be scientifically valid – is it? No – while treatment appears to have changed the behaviour, it is not replicated and this is the major disadvantage of the AB design. We can not say with absolute certainty that praise reduced the number of disruptions – there may have been another variable that coincided with the onset of treatment that caused that change.

 For example, in this example, what if one of the child’s peers happened to be sick during the treatment phase? It’s conceivable that the client’s disruptive behaviour changed not because of the praise but by the coincidental absence of a peer that was reinforcing that behaviour.

 The ABAB Design is also known as a reversal design because it returns back to baseline and treatment a second time. For example:

 You’ll see from the graph that the first baseline occurs, followed by implementation of treatment, then a return to baseline and then re- implementation of treatment. So an advantage of this design is that it shows both treatment effect and replication, so it is a scientifically valid research design. It is less likely that an unknown variable happened to be present precisely at the moment the treatment was implemented, then re-implemented.

 Disadvantage: There are two conditions under which we can NOT use an ABAB design. One, is if a return to baseline will result in harm to the individual, others or the space around them. An example would be finding a treatment to greatly decrease aggression – we wouldn’t return to baseline with the possibility that the aggression would return and someone could get hurt. The second condition is if learning took place as part of the treatment. For example, if my treatment resulted in you learning how to do the back stroke in swimming, I couldn’t return you to baseline.

 Multiple Baseline Across: (3 types)  Subjects: one behaviour, one setting, multiple

individuals ▪ Example: Have developed a treatment plan for reducing smoking

at a smoke-site for several individuals. One behaviour (smoking), one setting (smoke-site) and multiple individuals

 Behaviours: one individual, one setting, multiple behaviours

▪ Example: person has several nervous habits including forceful blinking, forearm muscle contraction and a vocal tic. One person, one setting (home) and multiple behaviours

 Settings: one individual, one behaviour, multiple settings

▪ Example: reducing smoking for one person at home, work and social functions.

 Graph

This is a generic Graph that could Depict any of the Multiple baseline types.

Note the phase line

 In MB designs, baseline data is taken for all 3 conditions (different people, different settings, different behaviours).

 Then, the treatment is introduced to one of the three conditions, while baseline data continues for the other two.

 After time has passed, the treatment is now introduced to the second condition, while the third is still held at baseline.

 This allows the researcher to see if the treatment had an effect, and allows him/her to replicate the findings across subjects, behaviours or settings. Therefore, it is a scientifically valid design. In addition, because it doesn’t return the individual to baseline, it can be used for injurious or learned behaviours that can’t be studied using ABAB. This is an advantage.

 There are no real disadvantages to Multiple Baseline except that they tend to be more complicated to do. In the event that an ABAB can be used, it is usually more beneficial to do so as the reversal provides a direct replication while the multiple baseline provides an indirect one.

 On the next slide, read the examples and decide which research design you’d use and why.

 Jack is interested in finding out whether a new reinforcement technique increases ability to rapidly decode letters in a sentence (he’s working with three kindergartners on pre-reading skills). Which of the above options would be a suitable research method and why?

 Sara has been working with a small child with Autism who engages in a number of severe self-injurious behaviours including wrist-biting, head banging and skin-picking. You’ve developed a procedure that you believe will decrease self-injurious behaviour. Which of the above options would be a suitable research method and why?

 You’re trying to help a friend who wants to eat more vegetables. You come up with a treatment plan that will increase the number of vegetables she will eat per day. Which of the above options would be a suitable research method and why?

 Post your Answers to Discussion if you’d like to have feedback. ☺