But there may have been a measurement error.

Using this property with a large item bank, test information functions can be shaped to control measurement error very precisely.

However, across a large number of individuals, the causes of measurement error are assumed to be so varied that measure errors act as random variables.

Examples of this include the failure to account for measurement error, or the failure to adequately control experiments for any parameters being measured.

The authors of this research conclude this measurement error may be sufficiently large to render many clinical decisions potentially erroneous.