How does Ixquick achieve such great results?

Each engine that Ixquick Metasearch queries has its unique strengths and vulnerabilities, and consequently some but not all of each engine's top choices are likely to be relevant for you.

Because engines have different vulnerabilities, irrelevant sites are unlikely to be prominently selected by multiple engines. When engines agree that a site is tops, and have reached that decision in different ways, the site is likely to be relevant.

So if you have constructed your search query carefully, a site that has been awarded multiple stars will probably contain information you will value.

Why order sites based on the number of engines that have chosen each site in the top ten for my search?

Many metasearch engines rank sites according to their own algorithms, rather than by how many engines liked the site a lot. While this sounds sophisticated, Ixquick believes that reasoning is flawed.

The star system works well because each search engine's primary function is to rank sites' usefulness given your search. Search engine developers have worked hard to perfect these relevancy scores, and have nonetheless come up with different algorithms.

Metasearch engines that purport to rank sites better than any search engine, without considering those search engines' rankings, are implicitly claiming to be great standalone search engines. Ixquick challenges them to abandon metasearching, create their own standalone search engine, and put every other search engine out of business by virtue of their purported superior results!

This is essentially an argument for a Random Walk of Search Engines.

Ixquick is not reporting an engine's results for my search!

There are two possibilities: either the engine was too slow in responding (in which case searching again should produce the responses), or Ixquick was being smart about your search.

Some search engines do not handle all functionality correctly, even though they will give you results. For example, if you put your term in quotes (a phrase), some search engines ignore the word order. Ixquick feels that if you care enough to use the quotes you won't want that engine's flawed results contaminating the result pool, and Ixquick intentionally omits that engine from that search to make sure your results are all top quality.