Three studies show that the retrieval process itself causes long-lasting forgetting. Ss studied 8 categories (e.g., Fruit). Half the members of half the categories were then repeatedly practiced through retrieval tests (e.g., Fruit Or). Category-cued recall of unpracticed members of practiced categories was impaired on a delayed test. Experiments 2 and 3 identified 2 significant features of this retrieval-induced forgetting: The impairment remains when output interference is controlled, suggesting a retrieval-based suppression that endures for 20 min or more, and the impairment appears restricted to high-frequency members. Low-frequency members show little impairment, even in the presence of strong, practiced competitors that might be expected to block access to those items. These findings suggest a critical role for suppression in models of retrieval inhibition and implicate the retrieval process itself in everyday forgetting. A striking implication of current memory theory is that the very act of remembering may cause forgetting. It is not that the remembered item itself becomes more susceptible to forgetting; in fact, recalling an item increases the likelihood that it will be recallable again at a later time. Rather, it is other items—items that are associated to the same cue or cues guiding retrieval—that may be put in greater jeopardy of being forgotten. Impaired recall of such related items may arise if access to them is blocked by the newly acquired strength of their successfully retrieved competitors (Blaxton & Neely,

Introduction One of the putative advantages of conscious knowledge is its flexibility: It can be applied in novel ways to novel situations (e.g. Baars, 1988). Unconscious knowledge on the other hand is commonly supposed to be routinized, inflexible, and triggered by specific perceptual cues (e.g. Berry & Dienes, 1993; Schacter, 1987; Shiffrin & Schneider, 1977). For example, consider knowledge of directions for travelling a certain route. If the directions are held consciously, any route can be readily followed . On the other hand, once a route has been travelled many times, the directions do not have to be held consciously in mind; but in this case, the knowledge is inflexible in that only one particlar route will tend to be followed. There are cases where conscious knowledge appears not to be flexibly deployed across domains, as illustrated by the literature on analogical transfer. People often do not notice that the known solution to a problem they have just come across could be u

Decision-support systems that help solving problems in open and weak theory domains, i.e. hard problems, need improved methods to ground their models in real world situations. Models that attempt to capture domain knowledge in terms of, e.g. rules or deeper relational networks, tend either to become too abstract to be efficient, or too brittle to handle new problems. In our research we study how the incorporation of case-specific, episodic, knowledge enables such systems to become more robust and to adapt to a changing environment by continuously retaining new problem solving cases as they occur during normal system operation. The research reported in this paper describes an extension that incorporates additional knowledge of the problem solving context into the architecture. The components of this context model is described, and related to the roles the components play in an abductive diagnostic process. Background studies are summarized, the context model is explained, and an example shows its integration into an existing knowledge-intensive CBR system.

This paper presents a model of context based on the roles and elements of various context types. Two important roles of context are related to the notions of relevance and focus. The former is important for the quality of the results reached by a problem solving or learning task, while the latter is important for the performance efficiency of the task. Problem solving can be viewed as search in a large problem space where search for different entities is invoked at different stages. Context has a pruning effect on search, increasing proportionally to the incompleteness of the information at hand. Depending on the type of memory structure to be searched for, different types of contexts assist the access to memory. We attempt to give an account of the various types of contexts that facilitate memory access and utilization for different type of tasks. The criteria for distinguishing between several types of context elements are presented, and a context ontology based on these criteria is suggested. We then show how this account is integrated with a case-based approach to clinical problem solving.

leamed to move a mobile by kicking and were tested 1 to 21 days later for retention of the newly acquired memory as a function of the training and testing contexts. In Experiment 1, decreasing the relative distinctiveness of the training and testing context did not impair retrieval of the newly acquired memory. In Experiment 2, however, testing in a different context completely eliminated retention after delays of 1 and 3 days, when retention was otherwise perfect; after progressively longer delays, retention improved paradoxically. The familiarity or novelty of the test context was not a factor in the failure of infants to recognize the mobile in the altered context after 1 day. In Experiment 3, the effect of an altered context was assessed in a reactivation paradigm. After the training memory was forgotten, infants were presented with the original mobile as a reminder and were tested for retention of the training memory 1 day later. When either the reminding context or the testing context was different, they exhibited no retention. These findings reveal that memory retrieval at 6 months is highly specific to the setting in which the memory is acquired. We propose that infants leam what specific events are associated with what specific places prior to the age when they can locomote independently and acquire a spatiotemporal map of the relations between thosfe places.