On-the-job caching is by far the predominant form of job training. Studies also indicate that it is the most effective form of job training. Yet, it also represents a significant investment considering that roughly 30% of a new worker's time is spent in on-the-job training during the first 90 days of employment, that productivity of experienced workers assigned to train new workers may decrease during the training period, and that new workers may make expensive mistakes. More
