Information search occurs in response to a recognized problem that is deemed important enough to resolve. Because an internal information search is much easier, less time‑consuming, and less expensive than an external search, internal search generally occurs first. This involves bringing relevant information from what is retained in long‑term memory into current memory. If no satisfactory solution can be obtained, then an external information search would follow if warranted by the nature of the problem and its importance. Information search also occurs on an ongoing basis for products and activities with which a consumer is involved. An external search for information can include: (a) the appropriate evaluative criteria for the solution of the problem, (b) the existence of various alternative solutions, and (c) the performance of each alternative solution on each evaluative criterion.