Calculating outliers with data sets containing two group

[JLit98]

Hi,

I have a data set containing two groups labelled as either HFD or HFDS, example below:

Treatment Mass
--------------------------
HFD 0.56
HFD 0.78
HFD -1.3
HFDS 1.4
HFDS 0.23
HFDS 0.10


I want to calculate outliers within the values of the Mass column, would I calculate outliers within each group or the entire data set?

 

[katxt]

If they are two different groups, I would do them separately.
How many in each group? How will you test them?