Cross referencing the results and finding similar sites at the top suggests these sites most accurately fit your criteria, while finding sites on one engine and not the other may suggest that these sites are coming from a different angle in relation to the search criteria, or serve a different purpose. Alternatively, there may be a more nefarious reason a site does not appear in each set of results. Comparing both sites may lead you to information that you otherwise may have missed and avoid some sites that you would be better off ignoring.

For example, searching for peanut butter on Microsoft Live, Google and Yahoo! returns a number of different results. Some of these are represented across all three engines and might be worth considering first. Broadly speaking, the remaining results tend to fall into a few different areas that, depending on why you searched for peanut butter, may be of more relevance:

(note that this is just one example and the recommendations may not hold true for other types of searches)

Using multiple search engines can also help to identify and avoid spam sites that have been specifically set up to feature highly in a particular search engine’s results. For example, if a site full of advertising has been engineered to feature highly in Google search results to lure people in to click on ads, the same site may not appear on the other engines.

For most people, their search engine of choice will come down to personal preference: what works best for them, what kinds of sites they prefer to look at, what gives them the information they need the quickest and what other services the site offers. However, by combining the efforts of multiple search engines, we can often get a more complete picture of what is available online that suits our needs and at the same time, check the validity of the results that are returned.