# Does sample size have measurement unit?

Sample size (n) refers to the number of participants or observations included in a study through which statistical inferences for the whole population are made. Can sample size have measurement unit, such as $$km^2$$ (kilometre square)?

In a paper on hydrology, researchers collected data from some areas, but they didn't specify the number of areas, rather said they collected the data from a area of size $$20km^2$$. Is this $$20km^2$$ the sample size in the study? I didn't find any other information in the paper which can be potential as a sample size.

Yes, $$km^2$$ can be used as a measurement unit but I would say that 20$$km^2$$ is not the sample size but rather than these 20 $$km^2$$ are part of the sample area of the study. For example, if we have 10 areas of 2 $$km^2$$ each, our sample size is $$n$$=10 with a total sample area of 20 $$km^2$$.
• Thank you for your reply. If another study report $12km^2$ of area with $3km^2$ for each, then it will become $n=4$. Is that the region behind using offset since each area size is variant? – user232597 Apr 18 at 3:51