Three experiments tested the efficacy of the phonetic mnemonic system under varying conditions of application. The first study attempted unsuccessfully to replicate and extend the work of Morris and Greer (1984), who had shown training in the phonetic mnemonic method to facilitate memorization of a serial list of two-digit numbers. In the present study, subjects trained in the phonetic mnemonic method failed to learn lists of two-, four-, and six-digit numbers better than control subjects. The second experiment partially replicated the first, the differences being that training in the phonetic mnemonic method was strengthened, and time allotted for number recall was extended. Under these circumstances the phonetic mnemonic group recalled the two-, four-, and six-digit numbers significantly better than the control groups, a finding conforming with Morris and Greer's (1984) results. The third experiment partially replicated the second, everything being the same except that, in this case, subjects constructed their own key words representing each number, instead of these words being supplied by the experimenter. Under these conditions, subjects trained in the phonetic mnemonic method recalled significantly fewer numbers than control subjects.The phonetic mnemonic method (Higbee, 1977: 135-151; Lorayne and Lucas, 1974: 83-93) is based on the assumption that words are easier to remember than numbers, and was devised especially to facilitate memorization of numeric material. In this system each of the digits 0-9 is represented by a consonant sound. The consonant sounds are linked together by vowels (which have no numerical value) to produce words, which represent the numbers to be remembered. For example, the word 'man' could represent the number 32 (i.e. rn = 3; the letter a has no numerical value; and n = 2). These words can subsequently be decoded to retrieve the original numbers. Cermak (1976) describes the phonetic mnemonic system as among the most powerful of the mnemonic techniques.Evidence concerning the effectiveness of the phonetic mnemonic method, however, is contradictory. Morris and Greer (1984) demonstrated that use of the phonetic mnemonic method improved retention of a serial list of two-digit numbers; Bruce and Clemons (1982) found that this method did not enhance the ability to remember conversions btween metric and standard measurement units (e.g. 1 kg = 2.2 Ib), and Patton (1986) found that not only did the phonetic mnemonic method fail to improve recall of numbers, dates, street addresses, and telephone numbeis, but that under some conditions this technique actually inhibited recall.The following set of three experiments was designed to resolve differences among previous studies and, in so doing, delineate the conditions under which the phonetic mnemonic method can or cannot be expected to be effective.