How Long Does a Disruption Last?

In the section on measuring lost time the teachers were asked to estimate how long a particular disturbance lasted. Here is a table with their estimates:

Table 15. Teacher's Estimates of the Length of a Disruption

This is a key table that defines the duration of a student's disruption.
Measured DisruptionInstructional Time Lost
in Minutes/Event
Multiple requests to follow directions.5
Failure to actively listen.25
Bad attitude/conflict4.5

As these estimates were contemplated, we discussed the framework in which the teachers should position their thinking. Consider that you are engaged in teaching and the entire classroom is in an instructional mode, i.e. in the “learning groove”. All of a sudden there is an outburst of anger by one of the students. Everything stops, the students raise their heads to listen and observe the disruption; the teacher immediately leaves instructional mode and enters a disciplinary mode. Minutes later the disruption seems to be over and the students go back to work. Are the students at this point truly able to focus on learning or is more time going to pass before the class is truly back into an instructional mode. The teachers were asked to estimate the time from the beginning of the disturbance to the return of the apparent instructional mode. Certainly, off the cuff, this is not easy to do. However, estimates were made and subsequently used to estimate the 62 minutes of classroom time lost each day to interruptions.  In business, the teacher’s “experienced based estimates” have the title of Bayesian estimates; such numbers, the quantification of human judgment, are used all of the time.

The illustrations below are another way to illustrate what is needed to visualize good lost time estimates.

This picture illustrates the effect from a single minor disturbance.


A disturbance begins when the pebble hits the water and ends when the waves are gone.

A disturbance begins when the pebble hits the water and ends when the waves are gone.

At times the disturbances come so rapidly that there is a possibility that the waves that may never subside.


Multiple disturbances can sometimes totally destroy the learning environment


The really serious classroom disturbances, a violent outbreak, a fight, a profane outburst, etc leads to a totally different outcome that may last for hours.

A MAJOR disruption can last a LONG time