Break it down, build it up

Thought of the day:

While commuting today, I wondered why we use the term "data analysis" or "data analyst".  I recalled that in chemistry class, we learnt that analysis means breaking things down while synthesis means building things up.

With regards to data, typically we try to collect data at the most detailed level and we build up messages and stories from the little pieces.  We don't break things down.  We can't break things down, in fact, if the data come to us in aggregated form.  (Think ecological fallacy.)

So why don't we say "data synthesis" rather than "data analysis"?