  Major search engines deploy personalized Web results to enhance users'
experience, by showing them data supposed to be relevant to their interests.
Even if this process may bring benefits to users while browsing, it also raises
concerns on the selection of the search results. In particular, users may be
unknowingly trapped by search engines in protective information bubbles, called
"filter bubbles", which can have the undesired effect of separating users from
information that does not fit their preferences. This paper moves from early
results on quantification of personalization over Google search query results.
Inspired by previous works, we have carried out some experiments consisting of
search queries performed by a battery of Google accounts with differently
prepared profiles. Matching query results, we quantify the level of
personalization, according to topics of the queries and the profile of the
accounts. This work reports initial results and it is a first step a for more
extensive investigation to measure Web search personalization.
