yes
ANOVA is used to find if the variance "within" the groups is significantly different from the variance " between" the groups, which means, is the variance consistent or the difference in varaince can be assigned to some external causes.
so essentially we need a number of 'groups'
but yes, if you are doing a study over some period of time, like the effect of a new acne cream, by taking results in may, june, july, and august, on Group A, you got yourself 4 group of readings, where you can do ANOVA to find if the variation in the effectiveness of your cream for the group is any different from teh variation over the months.
Shine on!
