Dale clarified that there is no rank or order to the level of efficiency in communicating through media that are concrete or abstract. Writing Space: Computers, Hypertext, and the Remediation of Print.
In fact, different media would be appropriate for specific learner and task.
One of the reasons is that people came back from the war with first-hand experience of rapid, massive training through the use of motion pictures and other AV media.
Since then, more people were receptive to the idea of learning from AV.
In addition, the baby boomer generation started going to school.
New schools were built with new AV equipment, and hence there was a need for technological and pedagogical support.
Figure 1: The original labels for Dale's ten categories are: Direct, Purposeful Experiences; Contrived Experiences; Dramatic Participation; Demonstrations; Field Trips; Exhibits; Motion Pictures; Radio; Recordings; Still Pictures; Visual Symbols; and Verbal Symbols.
Many misconceptions arose, that the amount of content retained increases with the level of concreteness of the learning experience.