18 Jan, 2013
Antecedents are things that happened prior to something else happening. Looking at an antecedent can
be helpful in figuring out why someone acted in particular way. For instance, Mary hit Julie. Why did
Mary hit Julie? She hit Julie because Julie tripped her. Julie's tripping Mary was the antecedent to Mary
Data usage and functional assessment
Stan has a diagnosis of trichotillomania. He is seeking help to stop pulling out his eyelashes and
the hair on his head.
Mya would like to lose weight. She has difficulty with emotional eating and with getting the
motivation to exercise.
What are target bahaviours?
-How would we measure Stan’s Target behaviour? (frequency of hair pulling in a day)
-How would we measure Mya’s target behaviour? (the kinds of foods she eats a day and the amounts of
How to measure behaviour? (exam question requires you to label examples with these)
Frequency (yes or no)
Magnitude (level/ intensity/ size)
Advantages of using a data sheet are that it helps people come and see a goal which leads to motivation
to continue to change the behaviour.
1 2 things before a behaviour is changed is identifying the behaviour and collecting data.
Identifying the connections between a target behaviour and its antecedents and consequences.
How do we identify these components? Eg. Losing weight, we 1 identify the food we eat (calorie intake), identify the antecedent (binge eating)
and then we observe the consequences.
Direct Assessment Methods
Observer measure variables through observation.
Unstructured descriptive assessment (naturalistic, eg. One way glass or stalking)
Structured descriptive assessment (test and measurements, eg. Unnaturalistic assessments )
What would be an example of a structured and unstructured assessment for Stan?
Structured- make him perform a work test/ stress test
What would be an example of a structured and unstructured assessment for Mya?
Structured- make her watch a sad movie or put her in a gym and see if she works out
unstructured- observation in natural field
What are some drawbacks to these methods?
1) If discovered in an unstructured assessment, the trust in the therapist will be lost and also the
behaviour will change
2) If the observed realise they were being watched, the would act differently
3) It is really expensive to hire someone to watch you all day
Time sampling (say for 1 hr, you take only 10 minutes of sample out of the 1 hr)
Indirect Assessment Methods
Abstract ways to measure variables
Interviews, questionnaires or rating scales
Drawbacks of using interviews/ questionnaires:
1) People do not always present the truth
2) People will try to present themselves in more socially accepted ways
3) When we use questionnaires to assess antecedents, we lose out on memory (not everyone will
remember the required information from their life)
Generally, the behaviour that happens exactly before the antecedent (hair pulling) Covert antecedent (the emotion right before eating)
Overt antecedent (fidgeting/ restlessness right before hair pulling)
Escape fro something unpleasant
Deciding on an intervention:
Adjust/ remove antecedents (changing consequences are better than moving antecedents)
Replace behaviours to achieve desirable consequences
Emphasize positive consequences of target behaviour
Systematic environmental manipulation (altering antecedents and consequences)
Laboratory or contrives setting
Manipulating only antecedents is less successful than manipulating consequences
Comparison of baseline to after the intervention
Limitations of functional analysis:
Previously relied on punishment
Difficulties with feasibility
Target behaviours at low frequencies
Dangerous target behaviours
AB design (cannot isolate the cause of the change)
Reversal designs (effect may not be reversible)
Multiple-Baseline (changes in one person may lead to changes in others. Changes in target1 can
lead to changes in target2.) Chapter notes:
(review chapter 3 and 13 diagrams)
An intervention is a program or period of time in which action is taken to alter an existing situation such
as target behaviour.
A baseline has two meanings: it can refer to the data collected before the intervention begins or to the
period of time during which those data were collected. If your intervention worked, the frequency of
pinching during intervention would decline from its baseline level. The main role of baseline data is to
give a reference point for comparison during the intervention phase, by comparing baseline and
intervention data, we can tell how making arithmetic calculations and tables can help. When our data
vary a great deal, we can make the picture clearer by calculating the mean, or average value for a set of
A table is a systematic arrangement of data or other information in rows and columns for east
examination. It organises the data visually allowing us to see patterns and make comparisons in the data
plainly and quickly.
Graphic analysis is where behaviour analysts inspect graphed data to evaluate whether the
behaviour changed substantially when intervention techniques were implemented. Although
there is no widely accepted, specific criterion for deciding whether graphed data do or do not
reflect “substantial” behavioural changes, there is agreement that the standards should be
Judging whether the program is working after a week or so of an intervention involves assessing
two trends or general patterns of change in the behaviour over time. One trend reflects whether
the behaviour improved from baseline to intervention and the second trend reflects whether
the behaviour has continued to improve across time during the intervention.
A trend line is a straight line that ‘best fits’ or represents all of the data points in a time period
through or very near the data point for the corresponding mean.
A few other approaches can clarify the results of a graphic analysis. One way is to check the
amount of overlap in the data points for baseline and intervention: the lower the overlap, the
greater the intervention’s effect. In the ideal condition that there is no overlap: