The ET Search feature does not distinguish between searches for:
word1 word2
word1 AND word2
"word1 word2"
2 methods of searching ET for a PHRASE "word1 word2" that I use:
1. Type
pair* trading
in the "Search by Keyword" box and check the radio buttons "search titles only" and "show results as threads". In this case, you'll get 61 results, most relevant: 39 for "pairs trading" and 22 for "pair trading" (hence *, the wild card character).
2. If you still want / need to run a full-text search, rather than titles only, use Google instead. If you have a Google toolbar at the top of your browser, simply type
"pairs trading" site:elitetrader.com
there (make sure to type the double quotes and leave no space after site: ). Otherwise, go to google.com and click on "Advanced Search". Similarly, you can run a separate search for "pair trading". Either way, you'll get about 322 results for the phrase "pairs trading" and 208 results for the phrase "pair trading" on ET.