Hello,
in a dot-probe experiment I want to present horizontally and vertically aligned dots. I have the problem that horizontal and vertical dots are not equally often presented.
So I first define the pictures 
<picture dot.pic>
/items = ("DotHor.png", "DotVer.png")
</picture>
then I try to assign the pictures depending on some list-value (see attached files):
if (list.pos.tar.neg.right.nextvalue == 1)       {picture.dot.pic.setitem("DotHor.png", 1); values.file.name = "DotHor.png";}
                  else if (list.pos.tar.neg.right.nextvalue == 2) {picture.dot.pic.setitem("DotHor.png", 1); values.file.name = "DotHor.png";}
                  else if (list.pos.tar.neg.right.nextvalue == 3) {picture.dot.pic.setitem("DotVer.png", 1); values.file.name = "DotVer.png";}
                  else if (list.pos.tar.neg.right.nextvalue == 4) {picture.dot.pic.setitem("DotVer.png", 1); values.file.name = "DotVer.png";}]
However, a frequency table shows that DotVer.png is presented more often than DotHor.png. 
                             soa166 soa32 soa83                                               DotHor.png target.neg.left        0     0     0           target.neg.right       6     6     6           target.neu.left        6     6     6           target.neu.right       0     0     0           target.pos.left        0     0     0           target.pos.right       0     0     0DotVer.png target.neg.left       12    12    12           target.neg.right       6     6     6           target.neu.left        6     6     6           target.neu.right      12    12    12           target.pos.left       12    12    12           target.pos.right      12    12    12
Running the experiment several times gives always the same frequency table. I can not find the programming error. Suggestions are heartily welcome.
Best wishes Jens