There were 100 trials in every session for both the partial-report and the whole-report
tasks. Data from the first 4 trials in every session were discarded. The 96 experimental
trials were divided into four blocks of 24 trials each.
For the partial-report task, the ISI value was held constant within a block. The ISI values
used in the first block were also used in the four warm-up trials. The order in which the
four ISI values were tested in a session was determined randomly for individual subjects.
Within a block of 24 experimental trials, the three probe tones were used equally often.
The choice of probe tones for the four warm-up trials was made at random and did not
have any bearing on the experimental trials. The specific order in which the three rows of
the partial-report display was probed was determined randomly within a block.
The sequence of events (as depicted in Figure 2) was thoroughly explained to the
subjects. They were given a thorough training on discriminating among the three probe
tones. The partial-report task did not start until the subjects could identify 30 tones (10
high, 10 medium, and 10 low, randomly arranged) without any error. Furthermore, the
subjects were always tested on tone discrimination before any subsequent sessions.
Whenever necessary, further practice on tone discrimination was provided before any
session began.
The subjects were told that the purpose of the experiment was to establish how fast they
could process visual information. The subjects were tested individually and were
instructed to recall the items in the positions in which they had been presented.
Results
The subjects' performance on the partial-report and the whole-report tasks were tabulated
according to the free-recall and the position-correct criteria. The two scoring criteria
produced the same pattern of results. However, the free-recall procedure gave a higher
absolute level than the position-correct criterion. For this report, only data scored with the
free-recall criterion were considered.
Because Sessions 1 and 2 were training sessions (on the partial-report task), data
collected in those sessions were not used in the analysis related to the display-instruction
compatibility hypothesis. Since partial report was tested in two sessions at every
compatibility level, data from the two occasions were averaged. Subsequently, the
subjects' partial-report performance was subjected to a 2 (instruction group) x 3
(display-instruction compatibility) x 4 (ISI) ANOVA with repeated measures on the latter
two factors. Data are shown in Figure 3.