Cost-Justifying Usability, 2nd Edition

this population when we do this kind of measurement; and the Measurement

Error is the amount of variation due to the inaccuracy of the questionnaire.

Because we have the standardization base for the Global subscale of WAMMI

(as well as all the other subscales, of course) and because we know how reliable

the subscale is, we can compute the previous quantities directly. This means we

know how much Measurement Error is involved and how much variation to

expect. These are important quantities to know: If we did not have the stan-

dardization base, we would have to estimate these quantities on the basis of the

actual sample we obtained. (How else would ...