TABLE I.

SHOWING IMMEDIATE RECALL AND RECALL AFTER TWO DAYS.

_M_.

Series. Im. Rec. Two Days. Im. Rec. Two Days.

N. O. N. O. V. M. V. M.

A^{1-4} 6 7 3 1 6 7 2 1 A^{5-8} 5(1) 6 3(1) 6 6(1) 7 5(1) 6 A^{9-12} 7 7 4 6 7 6(1) 7 6(1) A^{13-16} 4 5 2 2 5 3 2 2 Total. 22(1) 25 12(1) 15 24(1) 23(1) 16(1) 15(1) Per cent. 88 96 48 58 96 92 64 66

_S_.

Series. Im. Rec. Two Days. Im. Rec. Two Days.

N. O. N. O. V. M. V. M.

A^{1-4} 6(1) 6 0 0 7 7 0 0 A^{5-8} 6 7 1 3 6 7 0 3 A^{9-12} 7 6 2 2 5 7 0 0 A^{13-16} 5 5 0 0 5 5 3 0 Total. 24(1) 24 3 5 23 26 3 3 Per cent. 96 92 12 19 88 100 12 12

_Hu_.

Series. Im. Rec. Two Days. Im. Rec. Two Days.

N. O. N. O. V. M. V. M.

A^{1-4} 6 7 0 1 5 6(1) 0 2 A^{5-8} 5(2) 7 1(2) 1 7 7 1 0 A^{9-12} 6(1) 7 2 2 6 7 0 5 A^{13-16} 4(1) 4(1) 0 2 5 5 0 1 Total. 21(4) 25(1) 3(2) 6 23 25(1) 1 8 Per cent. 95 100 14 24 88 100 4 32

These results will be included in the discussion of the results of the _B_ set.

THE _B_ SET.

A new material was needed for foreign symbols. After considerable experimentation nonsense words were found to be the best adapted for our purpose. The reasons for this are their regularly varying length and their comparative freedom from indirect a.s.sociations. An objection to using nonsense syllables in any work dealing with the permanence of memory is their sameness. On this account they are not remembered long. To secure a longer retention of the material, nonsense words were devised in substantially the same manner as that in which Muller and Schumann made nonsense syllables, except that these varied regularly in length from four to six letters. Thus the number of letters, not the number of syllables was the criterion of variation, though of course irregular variation in the number of syllables was a necessary consequence.

When the nonsense words were used it was found that far fewer indirect a.s.sociations occurred than with nonsense syllables. By indirect a.s.sociation I mean the a.s.sociation of a foreign symbol and its word by means of a third term suggested to the subject by either of the others and connected at least in _his_ experience with both. Usually this third term is a word phonetically similar to the foreign symbol and ideationally suggestive of the word to be a.s.sociated. It is a very common form of mnemonic in language material. The following are examples:

cax, stone (Caxton); teg, bib (get bib); laj, girl (large girl); xug, pond (noise heard from a pond); gan, mud (gander mud).

For both of these reasons nonsense words were the material used as foreign symbols in the _B_ set.

The nonsense words were composed in the following manner. From a box containing four of each of the vowels and two of each of the consonants the letters were chosen by chance for a four-letter, a five-letter, and a six-letter word in turn. The letters were then returned to the box, mixed, and three more words were composed. At the completion of a set of twelve any which were not readily p.r.o.nounceable or were words or noticeably suggested words were rejected and others composed in their places.

The series of the _B_ set were four couplets long. Each series contained one three-letter, one four-letter, one five-letter, and one six-letter nonsense word. The position in the series occupied by each kind was constantly varied. In all other respects the same principles were followed in constructing the _B_ set as were observed in the _A_ set with the following subst.i.tutions:

No two foreign symbols of a series and no two terms of a couplet contained the same sounded vowel in accented syllables.

The rule for the avoidance of alliteration, rhyme, and a.s.sonance was extended to the foreign symbols, and to the two terms of a couplet.

The English p.r.o.nounciation was used in the nonsense words. The subjects were not informed what the nonsense words were. They were called foreign words.

Free body movements were used in the movement series as in the _A_ set. Rarely an object was involved, _e.g._, the table on which the subject wrote. The movements were demonstrated to the subject in advance of learning, as in the _A_ set.

The following are typical _B_ series:

B2. Nonsense words and objects.

quaro rudv xem lihkez lid cent starch thorn

B3. Nonsense words and verbs.

dalbva fomso bloi kyvi poke limp hug eat

B4. Nonsense words and movements.

ohv wecolu uxpa haymj gnash cross frown twist

The time conditions for presenting a series remained practically the same. In learning, the series was shown three times as before. The interval between learning and testing was shortened to 4 seconds, and in the test the post-term interval of _A^{13-16}_ retained (6 secs.).

This allowed the subject 9 secs. for recalling and writing each term.

The only important change was an extension of the number of tests from two to four. The third test was one week after the second, and the fourth one week after the third. In these tests the familiar word was always the term required, as in _A^{1-4}_, on account of the difficulty of dealing statistically with the nonsense words. The intervals for testing permanence in the _B_ set may be most easily understood by giving the time record of one subject.

TIME RECORD OF _Hu_.

Series. Im. Rec. Two Days. Nine Days. Sixteen Days.

B^{1-4} Feb. 12 Feb. 14 Feb. 21 Feb. 28 B^{5-8} Feb. 19 Feb. 21 Feb. 28 Mch. 7 B^{9-12} Feb. 26 Feb. 28 Mch. 7 Mch. 14 B^{13-16} Mch. 5 Mch. 7 Mch. 14 Mch. 21

The two half-hours in a week during which all the work of one subject was done fell on approximately the same part of the day. When a number of groups of 4 series each were to be tested on a given day they were taken in the order of their recency of learning. Thus on March 7 the order for _Hu_ was B^{13-16}, B^{9-12}, B^{5-8}.

Henceforth there was also rotation within a given four series. As there were always sixteen series in a set, the effects of practice and fatigue within a given half-hour were thus eliminated.

In the following table the results of the _B_ set are given. Its arrangement is the same as in Table 1., except that the figures indicate the number of absent terms correctly recalled out of four couplets instead of seven or five. Where blanks occur, the series was discontinued on account of lack of recall. As in Table 1., the tables in the first, third and fifth columns show successive stages of the same series. Immediate recall is omitted because with rare exceptions it was perfect, the test being given merely as an aid in learning.

TABLE II.

SHOWING RECALL AFTER TWO, NINE, AND SIXTEEN DAYS.

Days. Two. Nine. Sixteen. Two. Nine. Sixteen.

N. O. N. O. N. O. V. M. V. M. V. M.

Series. _M._ B^{1-4} 2(1) 4 1(1) 2 1(1) 2 4 4 4 2 4 2 B^{5-8} 3 1 2 1 1 1 2 2 2 1 1 1 B^{9-12} 2 3 0 3 0 2 3 2 2 0 2 2 B^{13-16} 2(1) 3 2(1) 0 2(1) 0 1 2 1 0 1 0 Total 9(2) 11 5(2) 6 4(2) 5 10 10 9 3 8 5 Per cent. 64 69 36 38 29 31 63 63 56 19 50 31

_S._ B^{1-4} 0 2 0 0 0 1 0 1 B^{5-8} 0 0 0 0 B^{9-12} 0 1 0 0 0 1 0 0 B^{13-16} 0(2) 1 0(2) 1 0(2) 1 0 0(1) 0 0(1) 0 0(1) Total 0(2) 4 0(2) 1 0(2) 1 0 2(1) 0 1(1) 0 0(1) Per cent. 0 25 0 6 0 6 0 13 0 7 0 0

_Hu._ B^{1-4} 1(1) 4 0(1) 1 0(1) 2 1 3 0 2 0 0 B^{5-8} 0 1(1) 0 0(1) 0 0(1) 0 1 0 1 0 1 B^{9-12} 0 1 0 0 0 1 0 0 0 1 0 0 B^{13-16} 0(1) 0 0(1) 0 0(1) 0 0 4 0 0 0 0 Total 1(2) 6(1) 0(2) 1(1) 0(2) 3(1) 1 8 0 4 0 1 Per cent. 7 40 0 7 0 20 6 50 0 25 0 6

_B._ B^{1-4} 1 1(1) 0 0 0 0(1) 0 0 B^{6-8} 1 2 1 2 1 1 1 0 1 0 1 0 B^{9-12} 0 2(1) 0 0(1) 0 0(1) 0(1) 2 0 2 0 1 B^{13-16} 1 3 1 1 1 1 1 2 0 1 0 1 Total 3 8(2) 2 3(1) 2 2(1) 2(1) 4(1) 1 3 1 2 Per cent. 19 57 13 21 13 13 13 27 7 20 7 13

_Ho._ B^{1-4} 3 2(1) 2 2(1) 1 0(1) 1(2) 1(2) 1(2) 0(2) 0(2) 0(2) B^{6-8} 1 1(1) 1 0(1) 1 0 0 1(1) 1 1 0 1 B^{9-12} 0(1) 1 0(1) 1 0(1) 0 1 1 1 1 0 0 B^{13-16} 0 0 0 0 0 0 0(1) 4 0(1) 2 0(1) 0 Total 4(1) 4(2) 3(1) 3(2) 2(1) 0(1) 2(3) 7(3) 3(3) 4(2) 0(3) 1(2) Percent. 33 30 25 23 17 0 17 58 25 33 0 8

_Mo._ B^{1-4} 3 3 3 1 4 1 0 2 0 2 0 2 B^{5-8} 1 4 1 1 1 2 1 2(2) 1 1(2) 1 1(2) B^{9-12} 2 4 2 4 1 4 0(1) 3(1) 1(1) 3(1) 1(1) 2 B^{13-16} 2(2) 4 2(2) 4 2(2) 2 1 4 1 4 1 4 Total 8(2) 15 8(2) 10 8(2) 9 2(1) 11(3) 3(1) 10(3) 3(1) 9(2) Percent. 57 94 57 63 57 56 13 85 20 79 20 69

Four presentations in learning.

Five presentations in learning.