Table 1
Arrangement of Experimental Sessions in Experiment 1
Session
|
Group |
Subject |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
|
9 | |||||||||
|
G1a,G2b |
1 |
Mc |
M |
Cd |
ICe |
IRf |
WRg |
IR |
IC |
|
C | |||||||||
|
G1 ,G2 |
2 |
M |
M |
IC |
IR |
C |
WR |
IC |
C |
|
IR | |||||||||
|
G1 ,G2 |
3 |
M |
M |
IR |
C |
IC |
WR |
C |
IR |
IC
aGl = Group l; given instruction to recall by row. b G2 = Group 2; given instruction to
recall by column. cM = trained with "mixed" cards. dC = compatible display instruction
(i. e., to recall by row and by column when given row and column cards, respectively).
eIC = incompatible display instruction (i.e., to recall by row and by column when given
column and row cards, respectively). fIR = irrelevant display instruction (i.e., to recall by
row or by column when given square cams). gWR = whole report.
Materials. The stimulus ensemble consisted of the following letters of the alphabet in
uppercase: B, C, D, F, G, H, J, K, L, M, N, P, R, S, T, V, W, X, and Z. Nine of them were
selected randomly without replacement, for use on any one trial.
Eight sets of 100 cards were prepared with a plotter driven by a UNIVAC 1160
computer. Nine letters of the ensemble were plotted on each card. The eight sets of cards
consisted of two "row" sets, two "column" sets, two "square" sets (see Figure 1 for some
examples), and two "mixed" sets. A set of "mixed" cards was made up of 32 "row," 32
"column," and 32 "square" cards.
A "row" card subtended a visual angle of 1 ° 59' in width and 3 ° 33' in height. A
"column" card subtended a visual angle of 3° 33' in width and 1° 59' in height. A square
display subtended a visual angle of 1 ° 59' in width and in height.
Three tones were used in the experiment. They were 5000 Hz (high tone), 1000 Hz
(medium tone), and 300 Hz (low tone).
Design. A 2 x 3 x 4 factorial design with repeated measures on the latter two factors was
used in Experiment 1. The first factor was recall instruction (i.e., recall by row or by
column), and it was a between-groups factor. The second factor was display-instruction
compatibility. Its three levels were compatible, incompatible, and irrelevant. The third
factor was the interstimulus interval (ISI), that is, the interval between the offset of the
stimulus and the onset of the probe tone. The four levels of ISI were 0, 150, 500, and
1,000 msec. Display-instruction compatibility and ISI interval were within-subject
factors.