We also tested an example of personalisation that Eli Pariser cites in his book.

BBC: Are we trapped in our own web bubbles?

Eli Pariser describes all this in great detail in his excellant book, The Filter Bubble.

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Eli Pariser, its executive director, says membership has increased since the ad appeared.

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That's the argument of Eli Pariser's book The Filter Bubble, which we explored in a film for Newsnight on Tuesday evening.

BBC: Are we trapped in our own web bubbles?

"Every major independent study and many major news organizations cast serious doubt on Petraeus' claims, " said Eli Pariser, executive director of MoveOn.org Political Action Committee.

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According to political activist and former executive director of moveon.org, Eli Pariser, Internet giants like Google, Yahoo, and Facebook have begun using algorithms to determine what we see and hear online.

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When we put these initial results to Eli Pariser on our Click programme a few weeks ago, he suggested that the apparent lack of personalisation may have been down to the word we chose.

BBC: Click listeners test 'filter bubble'

It does not refute Eli Pariser's hypothesis.

BBC: Click listeners test 'filter bubble'

Just as every talent has a flip side, one downside of such life-enhancing filtering is what Eli Pariser dubbed a filter bubble in which we narrow our interests and thus sometimes miss the serendipitous connections that can pull unexpected insights and friendships into our lives.

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