In my last blog post I was trying to understand (somewhat unsuccessfully) the mysyteries of Boolean search. Luckily, my Twitter network came to the rescue and @neiladam pointed out the flaw in my methodology, namely, the Boolean operators "OR","AND" or "NOT" all need to be in capital letters. I was using Boolify to teach the session and was thrown by the fact that the operators on the jigsaw pieces that Boolify uses to build their searches doesn't display the operators in capitals. Clearly Boolify themselves use Google Alerts and I was pleased that David Crusoe found time to comment on my piece taking on board the suggestion of putting the operators in capital letters.
I think they need to take a further step and parse complex search terms too. A complex search term is any search that consists of more than one word. So in my example I searched for Second World War. Google actually splits this up into a Boolean search thus:
Second AND World AND War
What this means in practice is that Google will find pages with these three words occuring anywhere, not just together, which is obviously what I meant it to do. This is an instance where you would need to use quotes to get it to search for the exact phrase "Second World War". It would be fantastic if Boolify automatically inserted the "AND" operator between complex search terms as well as having a quotation operator to allow the searching of phrases.
Rules for teaching Boolean Search
- The operators AND, OR, NOT must be in capital letters;
- Complex search terms containing more than one word automatically get parsed (split) using the AND operator;
- Use quotation marks for searching exact phrases.
To add a final spanner in the works, David points out that Google's search technology goes far beyond simple Boolean logic and uses all sorts of ways of ranking pages in terms of relevance, importance and authority, but I'm guessing you need a degree in computer science from Berkeley to understand how they do it.