Measuring Behavior

1. Measuring Behavior

2. Definition of Measurement • Is the process of applying quantitative labels to observed properties of events using a standard set of rules • Designed to know what is included and excluded

3. Why is Measurement Necessary? • Without measurement, science is only guesswork and opinion • Is a philosophy • ABA • Measure behavior to answer questions • Is the basis for talking about behavior • Allows you to determine if a behavior has changed

4. Practical Applications • Also used to measure behavior and evaluate effects of interventions • Used before, during, and after treatment • Used to guide decision making • Used to • Discontinue ineffective treatment • Continue or increase effective treatment

5. Benefits of Measurement • Optimize effectiveness • Verify legitimacy of treatments • Identify and end use of pseudoscience • Accountability • Meet ethical standards

6. Features of Measurement • Has dimensions or distinct features that can be measured • Three fundamental properties • Countability: behavior can be counted • Repeatability: Get the same result over and over • Temporal Extent: Duration of the Behavior • Temporal Locus: When does the behavior occur or stop

7. Counting • Number of responses emitted during an observation period • Periods can vary • Reported as frequency count • Problem • May not provide sufficient information for analysis • Duration may be more important variable

8. Repeatability / Reliability • Do you get the same result over and over? • When observing or examining a behavior , should get similar results during different observation periods. • If not, may have multiple stimuli controlling or influencing the behavior.

9. Rate/Frequency • Is a ratio of count per observation period • More meaningful than count alone • Include counting time for reference • Number of Responses / 10 Minute Period • Can also examine rate of correct vs. incorrect responses • Correct responses / Total responses • # Widgets made correctly / Time or Total Widgets made • Is helpful in skill development • Usually reported as number / standard unit of time

10. Guidelines When Using Rate • Take complexity of response into account • May need to break out into different responses • Is a very useful measure for free operants • Not appropriate • For responses within discrete trials (end of a class period) • For continuous behavior over extended period • Both can be adapted if needed.

11. Celeration • Is a measure of the change in rate of responding per unit of time • Behavior studying / 15 minutes • Examine stimuli influencing the behaivor • Reported using Standard Celeration Chart • Captures behavior acceleration and deceleration • Can be used to identify stimuli that are influencing behavior

12. Duration of Responding • The amount of time a behavior occurs • Total duration of session • Duration of each occurrence • Reported in standard time units • Counting plus duration measures provide different pictures of same behavior • May be critical in changing a behavior

13. Response Latency • Measure of elapsed time between onset of stimulus and initiation of response • Studying and acting out • Typically reported using mean, median, and range

14. Interresponse Time • Amount of time that elapses between two consecutive instances of a response class • Direct measure of behavior • Is related to rate of responding • Reported using mean, median, and range

15. Derivative Measures / Percentages • Are ratios formed by combining the same dimensional qualities • Expresses a proportional quantity • E.g., Correct to incorrect responses • Proportion of observation intervals when behavior occurred

16. Considerations for Using Percentage • Often is used incorrectly • Most accurate with divisor of 100 or more • May be misleading. Can indicate a behavior change when an outlier observation impacts the percentage • Has limited use because has no dimensional quantity • Often sets artificial limits on behavior change • May not be practical

17. Trials-to-Criterion • Measure of the number of response opportunities needed to achieve a predetermined level of performance • Can be combined or used to determine trials-to-criterion (e.g., rate) • Typically are calculated post facto • Used to compare effectiveness

18. Topography • Is the physical form or shape of a behavior • What does the behavior look like • Anger: Facial expression vs. hitting someone • Can have measurable dimension • Must be careful not to interpret. • Look at defined behvior • Malleable by consequences • Is not a fundamental quality of behavior

19. Magnitude • Is the force or intensity with which a response is emitted • Important parameter for some response classes • E.g., voice volume • Is not usually a fundamental quality of behavior • Try to measure with objective systems • Automatic Measuring Meter for Loudness

20. Procedures for Measuring Behavior • Typically involve one or a combination of these three: • Event recording • Duration • Time sampling methods

21. Event Recording • Uses procedures for detecting and recording the number of times a behavior is observed • Devices include: • Clickers, wrist counters, digital counters, masking tape, paper clips, match books, etc

22. Issues • Easy to do • Behavior must have discrete beginning and ending • Rate must not be too high • Inappropriate for behaviors with long duration

23. Problems • Need good observers • In applied settings (bars, restaurants, parks) may miss behaviors • Solutions • Work in teams • Have another team observe the first team • Recording devices – Cameras • Allows teams to examine and recheck behavior.

24. Time Recording • Procedures to measure duration, response latency, and/or interresponse time • Duration Techniques • Computer systems, stopwatch, wall clocks, tape recorder • Response latency and interresponse time techniques • Precise recording of duration between events of interest • Can use similar techniques

25. Time Sampling

26. Whole-Interval Recording Method • Used to measure continuous behavior • Brief intervals (5-15 seconds) • Record if behavior occurs throughout the interval, • Problems: • Risk of underestimation • Reported as percentage of intervals when behavior occurs

27. Partial-Interval Recording • Record if behavior occurs at any time during interval • Yes it occurs – No it does not • Multiple occurrences are scored as one • Does not capture duration • Allows recording of multiple behaviors • Reported as percentage of intervals when behavior occurred

28. Momentary Time Sampling • Records whether the behavior is occurring at the end of the interval • Does not require undivided attention • Misses much behavior • Best for continuous behavior • Reported as percentage of intervals when behavior occurred

29. Planned Activity Check • At end of interval, measure number of students engaged in target activity • Variation of momentary time sampling • Measures behavior of individuals within a group

30. Guidelines for Time Sampling • Use a timing device to signal beginning and end of observation • Increase accuracy • Not distracted by watching a stopwatch • Record a response for every interval (e.g., yes or no) • Prevents losing your place with blank intervals • Can use technology to help you • Cameras etc.

31. Artifactual Variability • Artifact is something that appears to exist because of the way it is examined or measured • Time sampling provides estimate of actual occurrences • Different procedures produce different results • Differences produce variability in data

32. Measuring Behavior by Permanent Product • Measures its effects on the environment • Ex post facto • All previous procedures can be applied to permanent product measurement • Products can be a natural or contrived

33. Advantages of Permanent Product Recording • Practitioner free to do other tasks • Possible measurement of otherwise inaccessible behavior • More accurate, complete, continuous • Easier data collection (IOA, treatment integrity) • Allows for the measurement of complex behavior

34. Determining Appropriate Use • Is real-time measurement needed? • Are moment to moment decisions required • Can behavior be measured as a permanent product? • Each occurrence must produce same product • Product can only be produced by target behavior

35. Other Issues • Reactivity effects • Observing behavior can change the behavior • Usually decreases over time • What are costs to obtain and measure the permanent product? • Availability, cost and effort of generating the product

36. Computer-Assisted Measurement • Data collection and analysis software combined • Multiple systems available • Sophisticated and easy to use • Laptops, hand-held computers, PDAs • Simultaneous recording of multiple behaviors across multiple dimensions

37. Conclusions • Measuring behavior is important • Allows you to determine if changes are occurring • Extremely important for working in applied settings