In this theoretical framework learning is viewed as an active, constructive process whereby the learner strategically manages the available cognitive resources to create new knowledge by extracting information from the environment and integrating it with information already stored in memory. This process is constrained by such cognitive factors as the duration and amount of information in short-term memory, the task-relevant information that is available in long-term memory, how this information is structured, the procedures that are activated to operate on it, and so on. Consequently, the process is sensitive to characteristics of the external environment, such as the availability of specific information at a given moment, the duration of that availability, the way in which it is structured, the ease with which it can be searched, and so on.