ment training helps improve employee performance on the job (a concept known as trans- fer of training, which is discussed in Chapter 5). Error management training is effective because it provides the opportunity for trainees to engage in metacognition, that is, to plan how to use training content, to monitor use of training content, and to evaluate how training content was used. This results in a deeper level of cognitive processing, leading to better memory and recall of training. Trainers should consider using error management training in the training program along with tradi- tional approaches by giving trainees the opportunity to make errors when they work alone on difficult problems and tasks while encouraging them to use errors as a way to learn. It is important to note that allowing trainees simply to make errors does not help learn- ing. For errors to have a positive influence on learning, trainees need to be taught to use errors as a chance to learn. Error management training may be particularly useful when- ever the training content to be learned cannot be completely covered during a training ses- sion. As a result, trainees have to discover on their own what to do when confronted with new tasks or problems. Massed versus Spaced Practice The frequency of practice has been shown to influence learning, depending on the type of task being trained. 41 Massed practice conditions are those in which individuals practice a task continuously without rest. Massed practice also involves having trainees complete practice exercises at one time within a lesson or class versus distributing the exercises within the lesson. In spaced practice conditions, individuals are given rest intervals within the practice session. Spaced practice is superior to massed practice. However, the effectiveness of massed versus spaced practice varies by the characteristics of the task. Task characteristics include overall task complexity, mental requirements, and physical requirements. Overall task complexity refers to the degree to which a task requires a number of distinct behaviors, the number of choices involved in performing the task, and the degree of uncertainty in performing the task. Mental requirements refers to the degree to which the task requires the subject to use or demonstrate mental skills or cognitive skills or abilities to perform the task. Physical requirements refers to the degree to which the task requires the person to use or demonstrate physical skills and abilities to perform and complete the task. Table 4.9 shows how tasks can differ. For more complex tasks (including those that are representative of training settings such as Web-based instruction, lecture, and distance learning), relatively long rest periods appear to be beneficial for task learning.