Focuses on variables that can be measured. Both measured with measuring instruments and other measures, such as processes, measuring, counting, it must be a variable that conveys the process that we want to learn it well.
Focus on variables that can be measured As measured by the Measurement and measurements, as other variables that must be considered by the media to the process we want to study it as well.
Focusing on the variables can be measured. When measured by the measuring instruments and measuring by measuring process such as counting to influence the media process that we want to learn it well!