In recent interviews and in his new book, "The Filter Bubble", Eli Pariser claims that personalization limits serendipity and discovery.
For example, in one interview, Eli says, "Basically, instead of doing what great media does, which is push us out of our comfort zone at times and show us things that we wouldn't expect to like, wouldn't expect to want to see, [personalization is] showing us sort of this very narrowly constructed zone of what is most relevant to you." In another, he claims, personalization creates a "distorted view of the world. Hearing your own views and ideas reflected back is comfortable, but it can lead to really bad decisions--you need to see the whole picture to make good decisions."
Eli has a fundamental misunderstanding of what personalization is, leading him to the wrong conclusion. The goal of personalization and recommendations is discovery. Recommendations help people find things they would have difficulty finding on their own.
If you know about something already, you use search to find it. If you don't know something exists, you can't search for it. And that is where recommendations and personalization come in. Recommendations and personalization enhance serendipity by surfacing useful things you might not know about.
That is the goal of Amazon's product recommendations, to help you discover things you did not know about in Amazon's store. It is like a knowledgeable clerk who walks you through the store, highlighting things you didn't know about, helping you find new things you might enjoy. Recommendations enhance discovery and provide serendipity.
It was also the goal of Findory's news recommendations. Findory explicitly sought out news you would not know about, news from a variety of viewpoints. In fact, one of the most common customer service complaints at Findory was that there was too much diversity of views, that people wanted to eliminate viewpoints that they disagreed with, viewpoints that pushed them out of their comfort zone.
Eli's confusion about personalization comes from a misunderstanding of its purpose. He talks about personalization as narrowing and filtering. But that is not what personalization does. Personalization seeks to enhance discovery, to help you find novel and interesting things. It does not seek to just show you the same things you could have found on your own.
Eli's proposed solution is more control. But, as Eli himself says, control is part of the problem: "People have always sought [out] news that fits their own views." Personalization and recommendations work to expand this bubble that people try to put themselves it, to help them see news they would not look at on their own.
Recommendations and personalization exist to enhance discovery. They improve serendipity. If you just want people to find things they already know about, use search or let them filter things themselves. If you want people to discover new things, use recommendations and personalization.
Update: Eli Pariser says he will respond to my critique. I will link to it when he does.