Interval #
1
2
3
4
5
6
7
8
9
10
Observer 1
X
0
X
X
X
0
X
0
0
X
Observer 2
X
0
0
X
X
X
X
0
0
X
Using the data in the table above, calculate inter-observer
agreement (IOA) using 3 different formulas. X = Behavior occurred,
0 = Behavior did not occur.
1. Formula for Interval-by-Interval IOA = # of intervals both
observers are in agreement/total # of intervals x 100
2. Formula for Scored Interval IOA = # of intervals both
observers recorded occurrence of behavior/total # of intervals at
least one observer recorded occurrence of behavior x 100
3. Formula for Unscored Interval IOA = # of intervals both
observers recorded non-occurrence of behavior/total # of intervals
at least one observer recorded non-occurrence of behavior x 100