Unlike the acquisition of knowledge, skill learning does not benefit from the instructor introducing the learner to new ideas or  prompting the learner to think about old ones in different ways. On the other hand, instructors should not confuse distractions during  skill learning with the legitimate use of distractions to help a learner learn how to manage his or her attention while coordinating  several tasks that have been mastered to some degree.  Blocked practice is practicing the same drill until the movement becomes automatic. Doing the same task over and over leads to  better short-term performance, but poorer long-term learning. It tends to fool not only the learner but the instructor into thinking the  skills have been well learned. While blocked practice enhances current performance, it does not improve either concept learning or  retrieval from long-term memory.  [Figure 3-19]  Blocked Practice  Random Practice  Random practice mixes up the skills to be acquired throughout the practice session. This type of practice leads to better retention  because by performing a series of separate skills in a random order, the learner starts to recognize the similarities and differences of  each skill which makes it more meaningful. The learner also is able to store the skill more effectively in the long-term memory.  Learners get to retrieve steps and parameters from long-term memory which helps learners recognize patterns between tasks.  Blocked practice performance scores well during the actual practice when compared to random practice performance. But on a test  given the next day, random practice does better than blocked practice. For long-term retention of aviation knowledge, the instructor  who uses well-written SBT which encourages random practice and leads to better retention of information.  How much practice is needed to attain proficiency? In planning for learner skill acquisition, a primary consideration is the length of  time devoted to practice. A beginning learner reaches a point where additional practice is not only unproductive, but may even be  harmful. When this point is reached, errors increase, and motivation declines. As a learner gains experience, longer periods of  practice are profitable.  Another consideration is the problem of whether to divide the practice period. Perhaps even the related instruction should be broken  down into segments, or it may be advantageous to plan one continuous, integrated sequence. The answer depends on the nature of the  skill. Some skills are composed of closely related steps, each dependent on the preceding one. Learning to pack a parachute is a good  example. Other skills are composed of related subgroups of skills. Learning to overhaul an aircraft engine is a good example.  Figure 3-19.  Pilot practices cross-wind landings repeatedly to improve performance.  3-27 