A very different way of testing memory involves simply showing subjects the words in the list and asking them whether they recognize the items. To keep the subjects honest these target words are mixed in with distractors (or foils) that they have not seen. The ACT-R model for this task is basically the one that Anderson and Bower (1972, 1974) developed 25 years ago where it is assumed that a memory trace is set up which encodes that an item occurred in a particular list.