Interval recording represents a prime example of a discontinuous time-based method for behavioral observation. Let’s take the example of “momentary time sampling” or MTS. To use MTS, an observer looks to see if the behavior occurs during a specified moment or a pre-selected interval of time (Cooper, Heron & Heward, 2007). Thus the name, momentary time sample.
Below let’s practice MTS. At the end of each 6 second interval, see if the observation target occurs. The target to observe: the appearance of a blue circle in the middle of the screen. Moving in the screen or leaving the screen do not count as the target observation. Anytime during the 1 second moment (i.e., 6, 12, 18, 24, 30, 36, 42, 48, 54), if you see the ball resting in the middle of the screen give it a check mark for a count of one.
Feel free to download the pdf recording sheet below and fill in the form.
What count did you end up with? Did you note more of the blue circles appeared than the momentary time sampling allowed you to count?
Some people choose to use interval recording methods like MTS to count behavior. Making the decision to measure only a sample of the full range of behavior creates an artificial ceiling. In Precision Teaching, we call all practices where we have an upper limit on what we can record a “record ceiling.”
In the previous exercise we can easily see the record ceiling. If you used the pdf form above, you can make out the number of times possible to count and record the target observation. The animated gif below shows we can only record a maximum of nine counts.
Therefore, the term record ceiling functionally defines its use. When making a record (of an observation), we encounter a ceiling (a limitation). Thus, on the Standard Celeration Chart, the record ceiling tells chart readers a ceiling occurred for measuring a specific data point.
If you go back to Figure 1 and count the frequency of the blue circle appearing, what do you come up with? The MTS and frequency count portray a stark difference in the frequency of recorded target observations. The MTS yielded a count of 2 appearances of the blue circle compared to 12 for the 59 second counting time.
On the Chart, we can now see the two frequencies and the destination of the record ceiling. The record ceiling draws our attention to something different about the observation.
By displaying the record ceiling, chart readers have additional information guiding their analysis. The data can only go as high as the record ceiling.
The record ceiling can come from other places aside from discontinuous time measures. Using percent correct, for example, also imposes a record ceiling. Let’s say we give a spelling test and have 10 items. Choosing percent correct imposes a ceiling of 100% (10 correct and zero incorrect).
Record ceilings, like the time bar, give the chart reader more information. And any extra details help the performer and educational team fully analyze the data and facilitate decision making.