Chapter 5 Flashcards
Improving and Assessing the Quality of Behavioral Measurement
Accuracy
The extent to which observed values, the data produced by measuring an event, match the true state, or true values, of the event as it exists in nature.
Believability
The extent to which the researcher convinces herself and others that the data are trustworthy and deserve interpretation. Measures of interobserver agreement (IOA) are the most often used index of believability in applied behavior analysis.
Calibration
Any procedure used to evaluate the accuracy of a measurement system and, when sources of error are found, to use that information to correct or improve the measurement system
Continuous Measurement
Measurement conducted in a manner such that all instances of the response class(es) of interest are detected during the observation period.
Direct Measurement
Occurs when the behavior that is measured is the same as the behavior that is the focus of the investigation.
Discontinuous Measurement
Measurement conducted in a manner such that some instances of the response class(es) of interest may not be detected.
Exact Count-Per- Interval IOA
The percentage of total intervals in which two observers recorded the same count the most stringent description of IOA for most data sets obtained by event recording.
Indirect Measurement
Occurs when the behavior that is measured is in some way different from the behavior of interest; considered less valid than direct measurement because inferences about the relation between the data obtained and the actual behavior of interest are required.
Direct Measurement
Occurs when the behavior that is measured is the same as the behavior that is the focus of the investigation.
Interobserver Agreement (IOA)
The degree to which two or more independent observers report the same observed values after measuring the same events.
Interval-By-Interval IOA
An index of the agreement between observers for data obtained by interval recording or time sampling measurement; calculated for a given session or measurement period by comparing the two observers’ recordings of the occurrence or nonoccurrence of the behavior in each observation interval and dividing the number of intervals of agreement by the total number of intervals and multiplying by 100.
Mean Count-Per-Interval IOA
The average percentage of agreement between the counts re-ported by two observers in a measurement period comprised of a series of smaller counting times; a more conservative measure of IOA than total count IOA.
Mean Duration-Per-Occurrences IOA
An IOA index for duration per occurrence data; also a more conservative and usually more meaningful assessment of IOA for total duration data calculated for a given session or measurement period by computing the average percentage of agreement of the durations reported by two observers for each occurrence of the target behavior.
Measurement Bias
Nonrandom measurement error; a form of inaccurate measurement in which the data consistently overestimate or underestimate the true value of an event.
Naive Observer
An observer who is unaware of the study’s purpose and/or the experimental conditions in effect during a given phase or observation period. Data obtained by a naïve observer are less likely to be influenced by observers’ expectations.
Observed Value
A measure produced by an observation and measurement system. Observed values serve as the data that the researcher and others will interpret to form conclusions about an investigation.
Observer Drift
Any unintended change in the way an observer uses a measurement system over the course of an investigation that results in measurement error; often entails a shift in the observer’s interpretation of the original definitions of the target behavior subsequent to being trained
Observer Reactivity
Influence on the data reported by an observer that results from the observer’s awareness that others are evaluating the data he reports.
Reliability
Refers to the consistency of measurement, specifically, the extent to which repeated measurement of the same event yields the same values.
Scored-Interval IOA
An interobserver agreement index based only on the intervals in which either observer recorded the occurrence of the behavior; calculated by dividing the number of intervals in which the two observers agreed that the behavior occurred by the number of intervals in which either or both observers recorded the occurrence of the behavior and multiplying by 100. Scored-interval IOA is recommended as a measure of agreement for behaviors that occur at low rates because it ignores the intervals in which agreement by chance is highly likely
Total Count IOA
The simplest indicator of IOA for event recording data; based on comparing the total count recorded by each observer per measurement period; calculated by dividing the smaller of the two observers’ counts by the larger count and multiplying by 100.
Total Duration IOA
A relevant index of IOA for total duration measurement; computed by dividing the shorter of the two durations reported by the observers by the longer duration and multiplying by 100.
Trial-by-Trial IOA
An IOA index for discrete trial data based on comparing the observers’ counts (0 or I) on a trial-by trial, or item-by-item, basis; yields a more conservative and meaningful index of IOA for discrete trial data than does total count IOA.
True Value
A measure accepted as a quantitative description of the true state of some dimensional quantity of an event as it exists in nature. Obtaining true values require “special or extraordinary precautions to ensure that all possible sources of error have been avoided or removed.
Unscored-IOA
An interobserver agreement index based only on the intervals in which either observer recorded the non-occurrence of the behavior; calculated by dividing the number of intervals in which the two observers agreed that the behavior did not occur by the number of intervals in which either or both observers recorded the non-occurrence of the behavior and multiplying by I 00. Unscored-interval IOA is recommended as a measure of agreement for behaviors that occur at high rates because it ignores the intervals in which agreement by chance is highly likely.
Validity
The extent to which data obtained from measurement are directly relevant to the target behavior of interest and to the reason(s) for measuring it.
