note that the recognition of an item can include context. That is, one can be asked whether an item has been seen in a study list. So even though one may have seen the word "apple" sometime during their life, if it was not on the study list, it should not be recalled. Item recognition can be modeled using Multiple trace theory and the attribute-similarity model. In brief, every item that one sees can be represented as a vector of the item's attributes, which is extended by a vector representing the context at the time of encoding, and is stored in a memory matrix of all items ever seen. When a probe item is presented, the sum of the similarities to each item in the matrix (which is inversely proportional to the sum of the distances between the probe vector and each item in the memory matrix) is computed. If the similarity is above a threshold value, one would respond, "Yes, I recognize that item." Given that context continually drifts by nature of a random walk, more recently seen items, which each share a similar context vector to the context vector at the time of the recognition task, are more likely to be recognized than items seen longer ago. Cued Recall In cued recall, an individual is presented with a stimulus, such as a list of words and then asked to remember as many of those words as possible. They are then given cues, such as categories, to help them remember what the stimuli were. An example of this would be to give a subject words such as meteor, star, space ship, and alien to memorize. Then providing them with the cue of "outer space" to remind them of the list of words given. Giving the subject cues, even when never originally mentioned, helped them recall the stimulus much better. These cues help guide the subjects to recall the stimuli they could not remember for themselves prior to being given a cue. Cues can essentially be anything that will help a memory that is deemed forgotten to resurface. An experiment conducted by Tulvig suggests that when subjects were given cues, they were able to recall the previously presented stimuli. Cued recall can be explained by extending the attribute-similarity model used for item recognition. Because in cued recall, a wrong response can be given for a probe item, the model has