As Web sites that publish guest hotel reviews become more influential, some hotels — from bed-and-breakfasts to large resorts — are going to greater lengths to ensure that their properties are rated highly. Their efforts, analysts say, range from encouraging guests to write flattering reviews to, in extreme cases, submitting bogus recommendations to Web sites.

The hotels justify their actions, the analysts say, as a counterweight to out-of-context rants by disgruntled guests; both sides are exploiting a new technology that lacks the safeguards of the traditional travel guidebooks, which are written by professional writers and edited for accuracy.

It was not always so. In the early days of hotel review sites on the Web, the Internet was a less diverse place, and the postings generally came from like-minded travelers, the experts say. But as more and more people are using the Internet to make travel decisions, there are more incentives, and opportunities, to manipulate reviews.

The major hotel chains deny that they try to influence online reviews in any way. But publishers at the most popular review Web sites say they have been inundated by fraudulent posts and have had to develop numerous measures to protect travelers.

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