  Searching for combinations in the frequency spectra of variable stars is a
commonly used method within the asteroseismological community, as harmonics and
linear combinations of individual frequencies are expected to appear not only
by chance, but also as a characteristic signature linked to different physical
phenomena, e.g., nonlinear oscillations, binarity, and rotation. Furthermore it
is very important to identify independent frequencies for modelling purposes.
We show that using high precision data sets delivered by recent space missions,
the distinction between combinations having a real physical meaning and
spurious combinations which only appear by chance gets more and more difficult.
We demonstrate how careful one should be with the interpretation of such
combination frequencies by presenting the statistical distributions derived
from artificial data sets. Based on comparisons to observations, we find that,
despite the high statistical probability of finding combinations in random data
sets (having similar properties to the ones of real stars), there is a
significant difference in the number of the lowest order combinations between
stars with and starts without real combination frequencies. This way, a search
for frequency combinations is very useful when interpreted properly, and when
results are compared to simulations.
