[Anechoic]

Are these data averaged across the entire year (including summers)? The summary is not clear about that, although it does include data from summer interviews.

If it is averaged across summers, you can have a teacher working 50 hrs/wk during the school year, 0 hours during the summer and have the average come out to less than 40.

[yummyfajitas]

From the third paragraph of the article I linked to:

With the exception of chart 1, all estimates presented are restricted to persons who were employed during the week prior to their interview and who did some work during that period. Thus, a teacher who was on summer or semester break during the week of the survey is not included in this analysis.

A great way to answer questions about an article someone cites is to actually read it.

[Anechoic]

I had read the article and read that section, but it doesn't answer my question - all that says is that teachers on break weren't included in the study, that doesn't say whether or not the data taken from the teachers included in the study were averaged across a (working or school) year just across the interviewees.

But thank you for your respectful response.

[yummyfajitas]

In the ATUS, interviewers collect data in a time diary format, in which survey participants provide information about "yesterday."

So no, it's not averaged across a year (unless the teacher worked a full year).