# Comparison of attraction/repulsion measures

1. Mar 14, 2008

### fer2000

Hello everybody!

I have a large set of items and, two-by-two, there exists some kind of attraction/repulsion that I have measured.
Under different circumstances this attraction/repulsion changes.
So, what kind of statistical/mathematical procedure can I use to measure whether the changes (for the whole set) are “large/small”, as well as if a subset of them (lets say the first ten items) the attraction is larger than in another subset (lets say the last ten items)?.

2. Mar 14, 2008

### reilly

First, you should provide a much more detailed description of your experiment. My initial thought would be a paired-comparison t-test; possibly an ANOVA approach. Much depends on what you do -- if time is involved, then the analysis can be tricky because of possible autocorrelations. Details, details, details.
Regards,
Reilly Atkinson

3. Mar 15, 2008

### fer2000

The situation is as follows,

My data are comprised in different matrices (each of the situations provide that information).
First one
x 1.3 -1.5 . . . . . .
1.3 x 1.2 . . . . . .
-1.5 1.2 x . . . . . .
. . . . . . . . . . . . . .

Second one
x 1.1 1.3 . . . . . .
1.1 x -0.2 . . . . . .
1.3 -0.2 x . . . . . .
. . . . . . . . . . . . . . .

Third one
x -0.1 0.3 . . . . . .
-0.1 x 0.4 . . . . . .
0.3 0.4 x . . . . . .
. . . . . . . . . . . . . . .

All of them are symmetrical and the diagonal does not make sense (I could write any number). Note that the dimension will be around 300 x 300 for each matrix.

How can I say if first one is closer (and how closer is) to second one than to third one (as well as any other combination)?
I do not mind the lapse of time between each of the situations (that provide each of the matrices), but an external condition that is the same for all the pairs that generate the matrix.

Thanks again.

4. Mar 15, 2008

### Staff: Mentor

Just out of curiosity, what is the connection of this with quantum physics?