Memory retrieval is the driving force behind all understanding; without it, even recognition-style understanding would fail. Therefore, it is necessary for creative understanding, since creative understanding is a superset of previous understanding behavior. In Lycanthrope, memory retrieval is used continuously to allow the reader to retrieve and utilize the concepts in the story which are familiar to them. For example, if the reader already possesses the concept of animal, then the reference to it in the third paragraph of Lycanthrope will be understood if the memory system can locate and retrieve the concept.
If memory retrieval is unsuccessful, the concept to be understood must possess some degree of novelty. This novel concept may still be understood if it has an analogue in memory. Understanding then becomes one of creating a mapping between the two concepts. Since no reasoner could be familiar with every possible concept which they could ever possibly encounter, analogical mapping is necessary for successful creative understanding. The story Zoo provides a good example of this form of understanding. In this tale, a great spaceship visits Earth each year to display Professor Hugo's Interplanetary Zoo. Tens of thousands of humans come to see the strange animals. The story concludes, however, with the ``animals'' of the zoo returning home to tell of their adventures going around to various planets to see the strange creatures that live on those far away worlds. The zoo is not for the humans' protection, it is for the ``animals.''
If an appropriate analogue cannot be retrieved from memory, the reasoner will need to try to dynamically create one by utilizing knowledge of similar concepts and general background information, a process known as base-constructive analogy. Consider a reader of Lycanthrope who possesses a concept of lycanthropy which is the ``standard'' mythological interpretation. There will be no analogue in memory with which to understand a human turning into a car. However, the reasoner may create such a base by combining elements from both lycanthropy and automobile knowledge. This ``mix-and-match'' approach to base creation has been discussed by several researchers with respect to creative design,invention, and conceptual change in science (see, for example, [#!creat:nersessian1!#,#!creat:clement1!#]); the present application is unique in that it applies a similar idea to the understanding process and develops a computational model of that process.
Should the above tasks fail to provide a satisfactory understanding, the reasoner may need to undergo problem reformulation. They might have misinterpreted what they were initially trying to understand. For example, in the story Men Are Different ([#!story:men!#]), a reader begins the story believing that the narrator is a human. At a point later in the story, the reader is explicitly told that the narrator is actually a robot. When this happens, the reader undergoes problem reformulation. Similarly, a reader of Lycanthrope must reformulate the problem of understanding lycanthropy once the character is transformed into an automobile rather than a wild animal.
While these precise tasks may not be necessary for creative understanding to occur, the functionality which they capture is necessary. A reasoner has to be able to retrieve concepts from memory, relate new concepts to existing ones, and create new concepts as needed to assist the understanding process. In addition, since mistaken understandings do occur during the reasoning process, it is necessary for a reasoner to be able to alter what they believe they are understanding. This will enable these ``mistakes'' to be recognized and other alternatives to be considered.