Unfortunately, Bjork points out, instructors are often fooled by retrieval success because they only observe the trainees during these sessions, and not later when they are using their training in real-life situations. Also, there is the tendency of instructors to gravitate towards techniques which produce retrieval success, rather than to use techniques which will guarantee better long-term performance. Trainees also prefer these approaches because they often have to evaluate instructors. He quotes a British study which showed postal workers were much more satisfied with a training program which used massed training schedules rather than one which involved spaced schedules, even though this was a less effective method of training when measured objectively (341).
Bjork cites studies which have shown that the more difficult the training program, the more effective it is at producing long-term learning (341). Little new learning occurs in training sessions unless there is a fluctuation in contextual cues. Increases in storage strength are a negatively accelerated function of current retrieval strength, and during training in which no new elements are introduced, very little new learning will occur.
Bjork next brings up the concept of perceptual fluency, which is the sense of familiarity evoked by presented materials (343). This fluency may often lead to errors, says Bjork, because the subject is used