Google: narrowing search gives more results

Factual Questions
1

I have a Google question. I suspect there’s a simple answer, and I’ll get my ass handed back to me *(grabs ankles in anticipation) *but I just can’t figure it out.

Why is it that when I type in “intracoronary nitroglycerin” I get 9,910 results, but when I type in “intracoronary nitroglycerin” and “angiography” I get 10,900? This is my most recent example, but I find this happens fairly frequently–trying to narrow a search by adding terms ends up giving me even more results.

Shouldn’t there be fewer sites/cites that have both terms? What am I missing here?

thank you.

2

My understanding is, Google will sometimes filter out results that they consider to be statistically identical. When you give more criteria it can help the algorithm decide what is “statistically identical”.

3

Thank you, Khadaji!

4

Does Google search with an “OR” between your two terms? If so, that would increase the number of results. AND would tend to decrease them.

5

Thanks Musicat. I just put the two words (quotation marks around “intracoronary nitroglycerin”) in, without OR or AND, and got the results shown above. I went just now and popped AND in there, and got the same 10,900.

I had thought, as you suggest, that AND would decrease the number of results, but apparently not. I think Khadaji’s algorithm is behind it.

6

Google defaults to AND, but will include results for OR occurrences in its count. It will do this regardless of whether you type AND or not. If you type OR, Google will return a few more pages.

Note that when you go several pages down the list, Google will eliminate more redundancies; by the time you get to page 3 of your search, their count is only 298.