"Marketing is getting more experimental, more aggressive and more direct, " says Andy Glaser, brand director at Heineken USA, who adds that the four annual tracking studies the company performs show that its U.S. Open sponsorship improves its recall with customers.

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For the new study, published in the Journal of the American Medical Association, Carnethon and her team reviewed data on five previous studies that were tracking people for heart disease risk factors.

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Catalyst, a nonprofit research and advisory group that studies women in the workplace, recently did a census tracking women executives in the largest companies and found dismal results.

FORBES: Drop-Offs

Yet, curiously, several academic studies have concluded that the Big Mac index is surprisingly accurate in tracking exchange rates over the longer term.

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Some brain-imaging studies suggest that people who regularly use the Internet become more skillful in tracking down data and some video games appear to help players improve visual acuity.

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Eye tracking technology leader SensoMotoric Instruments (SMI) from Germany today reveals an impressive piece of technology for user experience studies and gaze interaction applications in virtual environments.

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But other studies show majorities favoring the right to control how their data is used or opt out of online data tracking entirely.

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