How to interpret 'Chance Performance' output in SPSS?

#1
Hi,

I am trying to ascertain whether my participants performed better than chance on some tasks.

I have the average score and the chance score for each task.

In SPSS, i entered the chance score in the 'test value' box in the one-sample t-test dialogue box.

I want to know how to interpret the SPSS output.

Is the t-statistic the chance performance score?
if it is significant, does it mean the participants performed significantly (above/below) chance, depending on whether the t-statistic is above or below the mean?
What about if it is not significant?

Any help would be greatly appreciated.

Thanks a lot in advance.
 

Karabiner

TS Contributor
#2
Is the t-statistic the chance performance score?
No. Take a look at the forula for one-sample t-tests.
The t value is based on the difference between the
sample mean and the expected mean.
if it is significant, does it mean the participants performed significantly (above/below) chance, depending on whether the t-statistic is above or below the mean?
Yes.
What about if it is not significant?
Then either the participants' performance as not different
(or only marginally different) from chance performace, or
your sample size was to small.

Kind regards

K.