The importance of search and ranking in large web sites uses the excellent free WordPress plugin Relevanssi to power the site search with improved ranking. Over the years I have not experimented with the settings to see if I could improve the search results. This was a mistake! I was aware that the search did not recognise chemical formulae e.g. H2O because of the HTML tags <sub> and <sup> that are needed to get subscripts and superscripts to appear correctly. Recently I explored Relevanssi with the help of the plugin author to see if I could get the indexing feature to ignore these tags and replace them with no character (the default is a space which is a problem).

I also discovered that many users have been disappointed by my earlier settings when seeking information about chemical entities (screenshot). Relevanssi collects the failed searches (H2O, BF3, PF5, SF6, etc.) together to make a compelling argument for checking your own search results! I am delighted to report that the site search now works beautifully on the site for chemical formulae e.g. Na8[SiAlO4]6.(S3)2 Ultramarine. try it for yourself!

How to use Google to search and rank very large web sites

You can use Google advanced search to search just one site. In the normal Google search bar type “H2O” to search for H2O only on This works nicely. Google already knows about chemical formulae and is great at ranking but it is a bit more work to type

This trick is especially useful when searching University web sites.  In my experience, the inbuilt search function gives results but they are very poorly ranked. This means you have to look down the list of “hits” to find the one you require.  In Google and other search engines the most relevant hits rise to the top automagically.

Check out your own search feature on your own site and see if a) it finds all the relevant hits and b) ranks them sensibly. Relevanssi does this for me and so does Google (of course). This should work for other Chemistry web sites.



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