Approved For Release 2000/08/08
: CIA-RDP96-00789R003000490004-2
Target and Sender Dependencies
VI 20 March 1994
Analysis
We conducted two different analyses in this study:
(1) Our standard l-of-5 rank-order technique to construct effect sizes and p-values.
(2) An analysis of variance (ANOVA) to address the 2x2 questions.
Rank-Order
For each trial, there was a single response and its associated target pack (i.e., either static or dynamic).
An analyst, who was blind to the condition and target for the trial, was asked to rank-order five targets
(i.e., the intended target and four decoys) within the given pack. This was a forced ranking, so regard-
less of the quality of match between the response and targets, he/she had to assign a first place match, a
second place match, and so on for each of the five targets. The output from this part of the analysis was a
rank-order number (i.e., one to five, one corresponding to a first place match) for the correct target.
For each receiver, target type, and condition, there were 10 such rank-order numbers which constituted
a block of data. A rank-order effect size was computed for a block as:
£
‘.J
where 7?^
is the average rank for target type
i and sender condition j, and T^o
is the expected average
rank, which for this study is equal to three for all cases. N is the number of possible ranks and is equal to
five throughout this study. The effect size reduces to:
3 ~
R,.,
h
Analysis of Variance
A two-way analysis of variance (ANOVA) was computed for each receiver. The two primary variables
were target type and sender condition
(i.e., ANOVA main effects). Each of these variables possessed
the two states shown in Table
1 above.
Hypotheses
The overall null hypothesis was that
will not be significantly different from zero.
Using an F-test, we hypothesized that the quality oiAC does not depend upon a sender regardless of
target type.
Similarly, we used an F-test to test the hypothesis that the quality ofAC does not depend
upon target type, regardless of the sender condition.
The ANOVA also tests for potential interactions between the target and sender conditions. For exam-
ple, it might be that a sender is required for dynamic targets and not for static ones. We did not hypothe-
size with regard to interactions.
Approved For Release 2000/08/08
: CIA-RDP96-00789R003000490004-2
Approved For Release 2000/08/08
: CIA-RDP96-00789R003000490004-2
Target and Sender Dependencies
V1 20 March 1994
Effect Size Results
Five receivers completed 40 trials each. Table 2 shows the effect sizes computed for the 10 trials in each
cell. The underlined effect sizes indicate
1 -tailed significant results.
Receiver 009 showed significant
evidence for AC in the static target, no-sender condition ip < 0.02); receiver 372 in the static target,
sender condition; and receiver 518 in the static target, no-sender condition {p < 0.05). Combined, the
static, no-sender condition was significant (p < 0.02)
Table 2.
Effect Sizes
Receiver
Sender
Static
No Sender
Static
Sender
Dynamic
No Sender
Dynamic
009
-0.071
0.636
-0.141
0.141
131
-0.071
-0.071
0.212
0.495
372
0.707
0.141
-0.354
-0.283
389
0.141
0.212
0.000
0.000
518
-0.088
0.530
-0.495
0.283
Totals
0.198
0.297
-0.028
0.028
ANOVA Results
Table 3 shows the results of an ANOVA on these data.
Since there were 10 trials within each cell, the
degrees of freedom are the same for all receivers and, therefore, are only shown in the column headings.
Two receivers show significant main effects.
Receiver 372 showed a tendency to favor static over dy-
namic targets (i.e.p < 0.03), and receiver 518 showed a tendency to favor no sender conditions (i.e.,/7 <
0.04). Notice the underlined values in Table 3—for these receivers the ANOVA hypothesis that the data
were drawn from the same distribution
is rejected, and there were no significant interactions between
target type and sender condition.
Table 3.
ANOVA Results
Receiver
Sender Condition
Target Type
Interaction
F(l,36)
P-Value
F(l,36)
P-Value
F(l,36)
P-Value
009
0.38
0.54
0.68
0.42
2.08
0.16
131
0.18
0.67
1.66
0.21
0.18
0.67
372
1.01
0.32
5.47
0.03
0.61
0.44
389
0.01
0.91
0.33
0.57
0.01
0.91
CC
4.43
0.04
0.97
0.33
0.06
0.81
Approved For Release 2000/08/08
: CIA-RDP96-00789R003000490004-2