On 4/20/15 5:45 PM, Dan Goldman wrote:
Hello,
I have a question re: calculations of efficiency and vrf in optseq2.
We are running two tasks. One is a reasoning tasks, with trial lengths
of 12 seconds. The other is an embedded figures task with trial
lengths of 10 seconds. For both tasks, we have set a minimum ISI of 4
seconds and a maximum ISI of 10 seconds. In both tasks, we have two
conditions we want to compare and, thus, have devoted an amount of
time equal to 50% of the time devoted to tasks to total jitter time.
I'm not sure of your design here. If you have two conditions that you
want to compare to each other and to baseline, then you would give 1/3
of the total time to each. The baseline comparison is often of less
importance, so the null could be given a smaller proportion.
After running optseq2 for each task, we got the following statistics:
Task 1 (reasoning):
efficiency vrfavg
0.0485815 6.44628
Task 2 (embedded figures):
efficiency vrfavg
0.14506 9.22134
Is is a problem that the efficiency and average vrf are so much lower
for task 1 than task 2?
A problem in what way? If in terms of comparing reasoning vs figures, it
will not produce false positives, but you will be losing some power by
not balancing the design.
Thank you,
Dan
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