Mono-operation and mono-method bias. Use of only one measure per target and/or one method of recording (especially when there is more than one target) decreases the ability to draw conclusions. Using...

Mono-operation and mono-method bias. Use of only one measure per target and/or one method of recording (especially when there is more than one target) decreases the ability to draw conclusions. Using more than one would enhance conclusions by examining the extent to which multiple measures or multiple recording methods coincide. Example: Gye used only one self-report scale to measure outcome, and even though it showed improvement, it was hard to tell if the changes would have shown up using other methods of measurement.