hi, !

assuming the test groups in ranges: "A" = [B2:B4,B7:B9] and "B" = [C2:C4,C7:C9]

=ttest(subtotal(9,offset(b2,{0;1;2;5;6;7},)),subto tal(9,offset(c2,{0;1;2;5;6;7},)),1,2)

(same result as using contiguous ranges)

hth,
hector.

__ OP __
I have data from two groups interleaved in the same column.
For the sake of simplicity, let's imagine group A: rows 1-3,7-9; group B: rows 4-6,10-12.
I want to compare groups A and B with a ttest -witout having to displace values everywhere-.
However, I can not specify ranges, otherwise the ttest gets too many arguments
(the coma for specifying ranges is taken as the coma that separates the different arguments.
I tried using named selections (shift+click on cells of group A, then name 'groupA'
at the left of the function bar, similar for group B), but it still doesn't work. I still get ERROR IN VALUE.
Am I missing a simple workaround for that ?