A wide range of models exist concerning order recall. The example outlined above is just one. It has been run successfully, though, in the form of computer simulations to see whether the outcome matches the data from human performance, and the match is good. It is also the case that data exist from animal studies indicating a capacity to keep track of time in a manner similar to the functions posited here (Church & Broadbent, 1990; Gallistel, 1990; Treisman, Cook, Naish, & MacCrone, 1994).
As described above, if a list of items including BOOK TREE DAFFODIL HOUSE is learned, then the learner is likely to report BOOK TREE DAFFODIL HOUSE in the original order. The historical assumption here had been that the word items are linked directly to one another, on the basis of contiguity. But it has been established that forgetting a given item does not impair the recall of the next item to any significant extent: the individual who forgets TREE is in general just as likely to remember DAFFODIL as the individual who remembers TREE (Baddeley, Conrad, & Hull, 1965). Given this discovery, probably the majority of psychologists in this area believe that the various word items are not directly linked to one another. That is, there is no “thread” leading from the representation of BOOK to the representation of TREE in the learner’s LTM. Owing to these and some related findings, new models have been developed. Researchers, or some of them at least, went back to the drawing board.