September 2004: MDO now means: Missing Data Out!
The power of the MDO option has been increased. Including MDO on an affective subtest's *sub line now gets Lertap to correct its brief stats report (such as Stats1b) for unequal response n's. Items with missing data may now have their statistics adjusted so that they're based only on valid item responses.
This is likely to be a handy revision for survey users. Read more about it by clicking here.