However, many are critical of these units due to the arbitrary use of time as the basis for measuring educational attainment. Generally, the criticism is that student learning varies greatly even among individuals who teach the same material. Variations are even greater among the various faculty members, departments, topics, schools, colleges, and universities. This has become an even greater concern in this era of distance learning and telecommunication. Frustration is particularly high among those involved with transfer of credit among institutions.