Overview • Characteristics of behavior to assess • Methods of assessment • Ensuring accuracy
Direct Assessment • Behaviors directly observed • Advantage: • More accurate than indirect assessment • Disadvantages: • Time consuming • Observers need to be trained • Cannot monitor covert behaviors
Characteristics to Consider • Topography • Amount • Intensity • Stimulus control • Latency • Quality
1. Topography • The form of a particular response • Physical appearance or movement involved with the response • Can use various methods to help visualize and record
2. Amount • Measured by frequency and duration • Frequency • Number of instances a behavior occurs in a given period of time • Rate • Duration • How long a behavior lasts • Relative Duration • Length of time a behavior occurs within some period
Graphs • Frequency Graph • Each data point represents total number of instances of behavior in that time period • Cumulative Graph • Each data point represents a total number of responses up to that point
3. Intensity • Force of a response • Use various devices to measure force • Pitching • Strength
4. Stimulus Control • Behavior occurs in the presence of certain stimuli and not others • High correlation between occurrence of stimuli and response?
5. Latency • Amount of time between stimulus and response • How long before you respond • Ex: Alarm clock
6. Quality • How well an activity is performed • Arbitrary designation of one or more of characteristics of behavior • Good student? • Good athlete?
Percentage • How many in a group respond • Evaluating group treatment • EX: safe sex practice
Strategies for Recording Behavior • Continuous recording • Recording every instance in a specified time segment • Interval recording • Specify block of time • Divide time into equal short intervals • Does behavior occur or not during interval? • Partial-interval recording • Most frequently used • Behavior recorded a maximum of once during interval • Whole-interval recording • Only record if occurs over entire interval
Strategies for Recording Behavior • Time-sampling recording • Interval recording • Intervals are separated by longer periods of time • Momentary time sampling • Record if behavior occurs at specific points in time
Accuracy of Observations • Sources of Error • Response definition too vague or unclear • Observational situation makes observations difficult • Poor training of observer • Poorly designed data sheets • Interobserver reliability (IOR) • Do ratings of different observers agree?