A couple of weeks ago I read an interesting blog post about comparing the relevance of three different search engines. This made me start thinking of relevance and how it’s sometimes overlooked when choosing or implementing a search engine in a findability solution. Sometimes a big misconception is that if we just install a search engine we will get splendid search results out of the box. While it’s true that the results will be better than an existing database based search solution, the amount of configuration needed to get splendid results is based on how good relevance you get from the start. And as seen in the blog post, it can be quite a bit of different between search engines and relevance is important.

So what is relevance and why does it differ between search engines? Computing relevance is the core of a search engine. Essentially the target is to deliver the most relevant set of results with regards to your search query. When you submit your query, the search engine is using a number of algorithms to find, within all indexed content, the documents or pages that best corresponds to the query. Each search engine uses it’s own set of algorithms and that is why we get different results.

Since the relevance is based on the content it will also differ from company to company. That’s why we can’t say that one search engine has better relevance than the other. We can just say that it differs. To know who performs the best, you have to try it out on your own content. The best way to choose a search engine for your findability solution would thus be to compare a couple and see which yields the best results. After comparing the results, the next step would then be to look at how easy it is to tune the relevance algorithms, to what extent it is possible and how much you need to tune. Based on how good relevance you get from the start you might not need to do much relevance tuning, thus you don’t need the “advanced relevance tuning functionality” that might cost extra money.

In the end, the best search engine is not the one with most functionality. The best one is the one that gives you the most relevant results, and by choosing a search engine with good relevance for your content some initial requirements might be obsolete which will save you time and money.