[From Rick Marken (950121.1800y)]
Well, I do seem to have caught up to some extent with CSG-L so, what
the heck, I'll just have to work with a two day lag.
Bruce Abbott (950116.1730 EST) said:
Do the PCT-analysis programs you have written estimate the reference
value from the data? When the data set contains only cursor and handle
positions, (i.e., lacks the disturbance tables), the disturbance values
can be calculated exactly only if the reference values are known
Tom Bourbon (950119.1445) --
That sounds a little strange. Momentary cursor position is
determined entirely by handle position plus disturbance: c = h + d.
Bruce Abbott (950120.2030 EST) replies, authoritatively:
I've already explained this in my reply to Rick's similar comment.
The cursor position data include an [unknown] added constant which
is the screen x-position of the targets.
.
.
.
In other words, it still doesn't matter, unless c=d+h+t, which it does,
so it does matter. Rick, when I'm right, I'm right. (;->
But if c = d+h+t then t IS KNOWN; you added it!! There is nothing to
"estimate" whether you call t a reference value, a target or a toosie roll.
The value of t is right there in your source code. Tom (like me) asked
you about your strange comment (about having to estimate the reference
value in order to compute d) because it suggested a bit of confusion on
your part about the difference between the reference value (which exists in
a person's brain) and the target (which exists on the screen). The
person's reference for the position of the cursor is quite independent
of (and may be quite different than) the target position on the screen.
So it seems that, sometimes, when you're right, you're wrong;-)
By the way, you didn't choose to answer my question about the
implications of your excellent analysis of the data from the three
cursor experiment. I said:
You've done some mighty high-powered analyses of this data; what
do you think the results of these analyses imply about the
experimental and statistical methods used in psychology?
What DO you think these analyses imply about the experimental and
statistical methods used in psychology? Nothing? Something? You are
certainly the expert in experimental and statistical methods in
psychology. I think your answer would be most valuable -- and,
possibly, even right;-)
Best
Rick