If the memory has partially degraded, the item must be reconstructed through trace redintegration. If the process of redintegration was successful, the memory is recalled correctly. Thus, the probability of correct recall (formula_1) is:formula_2Where: formula_3 is the probability of trace being intact, and formula_4 is the probability of correct redintegration.If the trace is neither intact nor successfully completely redintegrated, person fails to accurately recall the memory. Schweickert proposed that the redintegration of memory trace happens through two independent processes. In the lexical process, the memory trace is attempted to be converted into a word. In the phonemic process, the memory trace is attempted to be converted into a string of phenomes. Consequently, the probability of correct redintegration (formula_4), becomes a function of formula_6 (lexical process) and/or formula_7 (phonemic process). These processes are autonomous, and their effect on formula_4 depends on whether they take place sequentially or non-sequentially. Schweickert’s explanation of trace redintegration is analogous to the processes hypothesized to be responsible for repairs of errors in speech. Though Schweickert indicates that the process of trace redintegration may be facilitated by the context of the situation in which recall takes place (e.g. syntax, semantics), his model does not provide details on the potential influences of such factors. Schweickert’s model was extended by Gathercole and colleagues (1999), who added a concept of degraded trace. Their model of the multinomial processing tree included an additional node, which represents a decayed memory. Such degraded trace can no longer undergo redintegration, and the outcome of recall is incorrect. Thus, the probability of correct recall (formula_1) changes to: formula_10Where:formula_11 is the probability of trace being intact, formula_4 is the probability of correct redintegration, and formula_13 is the probability of trace being entirely lost. The main criticism of Schweickert model concerns its discrete nature. The model treats memory in a binomial manner, where trace can be either intact, leading to correct recall, or partially decayed, with subsequent successful or unsuccessful redintegration. It does not explain the factors underlying the intactness, and cannot account for the differences in the number of incorrect attempts of recall of different items. Moreover, the model does not incorporate the concept of the degree of memory degradation, implying that the level of trace’s decay does not affect the probability of redintegration.