This question assesses understanding of both the definition of whole interval recording and best practices for interval duration in discontinuous measurement 1 Whole Interval Recording Definition For an interval to be recorded as an occurrence correct the target behavior must occur throughout the entire duration of that interval This method tends to underestimate the actual occurrence of the behavior making it suitable for behaviors targeted for increase Option A is incorrect because some part of the interval describes Partial Interval Recording not Whole Interval 2 Optimal Interval Duration When using discontinuous measurement methods like whole interval shorter intervals are generally preferred especially when the goal is to increase a behavior Shorter intervals eg 1minute intervals as in Option B versus 5minute intervals as in Option C offer several advantages Increased Sensitivity They are more sensitive to subtle changes or occurrences of the behavior More Data Points They yield a larger number of data points within the observation period 30 intervals vs 6 intervals providing a richer dataset for analysis Reduced Underestimation While whole interval always underestimates shorter intervals can help mitigate severe underestimation For instance if a client remains seated for 45 minutes in a 5minute interval it would be recorded as a nonoccurrence In contrast with 1minute intervals those 45 minutes could result in 4 correct recordings providing a more accurate representation of the clients progress Therefore 30 oneminute intervals Option B are superior to 6 fiveminute intervals Option C for this purpose Option D describes Momentary Time Sampling not Whole Interval Recording