  Search engines can be considered as a gate to the world of WEB, and they also
decide what we see for a given search query. Since many people are exposed to
information through search engines, it is fair to expect that search engines
should be neutral; i.e. the returned results must cover all the elements or
aspects of the search topic, and they should be impartial where the results are
returned based on relevance. However, the search engine results are based on
many features and sophisticated algorithms where search neutrality is not
necessarily the focal point. In this work we performed an empirical study on
two popular search engines and analysed the search engine result pages for
controversial topics such as abortion, medical marijuana, and gay marriage. Our
analysis is based on the sentiment in search results to identify their
viewpoint as conservative or liberal. We also propose three sentiment-based
metrics to show the existence of bias as well as to compare viewpoints of the
two search engines. Extensive experiments performed on controversial topics
show that both search engines are biased, moreover they have the same kind of
bias towards a given controversial topic.
