Sue Shellenbarger

Preteens and teens may appear dazzlingly fluent, flitting among social-media sites, uploading selfies and texting friends. But they’re often clueless about evaluating the accuracy and trustworthiness of what they find.

Some 82% of middle-schoolers couldn’t distinguish between an ad labeled “sponsored content” and a real news story on a website, according to a Stanford University study of 7,804 students from middle school through college. The study is the biggest so far on how teens evaluate information they find online. Many students judged the credibility of newsy tweets based on how much detail they contained or whether a large photo was attached, rather than on the source. More than two out of three middle-schoolers couldn’t see any valid reason to mistrust a post written by a bank executive arguing that young adults need more financial-planning help. And nearly four in 10 high-school students believed, based on the headline, that a photo of deformed daisies on a photo-sharing site provided strong evidence of toxic conditions near the Fukushima Daiichi nuclear plant in Japan, even though no source or location was given for the photo.

For most people, a cabana on the beach is the ultimate refuge from their office. For others, it is the office. Beach clubs are expanding Wi-Fi and members are paying to install internet routers and phone lines in their cabanas to telecommute from the beach.