Evidence-based Medicine and Dentistry

Google Scholar (GS) can be great tool for answering your questions. Its ranking algorithm works very well and considers citation counts, which can help boost higher-impact papers to the top of the results (for better or worse). Also, it tends to be pretty good at resolving word variations so you don't have enter plurals, for instance. Still, you should include synonyms when you know them. The biggest downside may be that there are no article type limits or other sorts of management tools like the ones you find in PubMed.

The search window is more than just a white rectangle you type words into. Keep in mind all the general things you learned about search like avoiding abbreviations and using nouns. GS is not a true natural language processor, so skip all the adjectives, adverbs, and verbs just like you would in PubMed. As an example, consider this question:

What is mechanism of resistance to tyrosine kinase inhibitors of the EGFR exon 20 insertion in lung adenocarcinoma?

We can start by entering the most important, most specific concept:

"exon 20"

I've used quotes just to keep these words together. Google will make an exact match with the contents of the quotes. We can then add the next best concept:

"exon 20" (EGFR|ERBB)

I've added EGFR, plus a synonym, ERBB (that’s what we used to call it back in the day). We could add other synonyms as well (NCBI's Gene database is a great resource for gene names and synonyms). The "pipe" | is an OR operator, and it can be found on the backslash key. Sure, you can use OR, but it takes four characters instead of one. GS has a 256-character limit, so | can be useful. Plus, it just looks cool. You don't really need the parentheses when you use |, since Google interprets a space as an AND operator, and ORs have priority (they get done first). But sometimes it's easier to see what you're doing by including parentheses. Delete them if you run up against the character limit.

If you ran the search just like we did above, you'd start to get useful results. But let's limit it a bit more:

"exon 20" (EGFR|ERBB) lung cancer (resistance|resistant) "tyrosine kinase inhibitors"

You could probably leave off the tyrosine kinase inhibitor bit. What else would an EGFR insertion be resistant to, anyway?

And you can get more specific still. In PubMed you can restrict a search to a specific field, and you can in GS, too. There just aren't so many fields. The most useful is title, which you can do with the "intitle:" operator:

intitle:"exon 20" (EGFR|ERBB) lung cancer (resistance|resistant)

All the records returned by this search will have "exon 20" in the title. The operator will only affect the string it precedes, and you can only use it once in a search.

There really isn't any truncation in Google. The asterisk * is a wildcard that stands in for one or more words, rather than characters. So, this search (use quotes as in the example):

"tyrosine * inhibitors"

captures both "tyrosine kinase inhibitors" and "tyrosine phosphatase inhibitors"

There is one more operator you should know about, "site:". This operator will limit the search to the internet domain that it precedes. So, this search:

site:biorxiv.org covid|covid19 vaccines|vaccination|immunization

will return material only from bioRxiv. It works for medRxiv.org, PubMed (with pubmed.ncbi.nlm.nih.gov), the WHO (who.int), or any other domain that gets indexed in GS.

Happy Searching!