http://www.collegeresults.org/aboutthedata.aspx

From the description, it looks like students who transfer to other colleges would be part of the 73 percent figure. So if it included only bona fide dropouts it would be lower.

On the other hand, schools are allowed to exclude (i.e. not count as dropouts) students who leave school for various specific reasons such as serving in the armed forces.

Another point to note is that ASU has the lowest or next to lowest graduation rate (depending on whether you look at four-year or six-year rates) of all comparable institutions in the Education Trust data. Clearly dropouts are a serious problem at ASU regardless of how many of those 73 percent are bona fide dropouts.

Calculating an accurate dropout rate in the absence of reliable information is of course a very tricky business, and I suspect these Education Trust figures are the closest thing we have to a good measurement.