tailieunhanh - Building Web Reputation Systems- P5

Building Web Reputation Systems- P5:Today’s Web is the product of over a billion hands and minds. Around the clock and around the globe, people are pumping out contributions small and large: full-length features on Vimeo, video shorts on YouTube, comments on Blogger, discussions on Yahoo! Groups, and tagged-and-titled bookmarks. User-generated content and robust crowd participation have become the hallmarks of Web . | Users comments are usually freeform unstructured textual data. They typically are character-constrained in some way but the constraints vary depending on the context the character allowance for a message board posting is generally much greater than Twitter s famous 140-character limit. In comment fields you can choose whether to accommodate rich-text entry and display and you can apply certain content filters to comments up front for instance you can choose to prohibit profanity or disallow fully formed URLs . Comments are often just one component of a larger compound reputation statement. Movie reviews for instance typically are a combination of 5-star qualitative claims and perhaps different ones for particular aspects of the film and one or more freeform comment-type claims. Comments are powerful reputation claims when interpreted by humans but they may not be easy for automated systems to evaluate. The best way to evaluate text comments varies depending on the context. If a comment is just one component of a user review the comment can contribute to a completeness score for that review reviews with comments are deemed more complete than those without and in fact the comment field may be required for the review to be accepted at all . If the comments in your system are directed at another contributor s content for example user comments about a photo album or message board replies to a thread consider evaluating comments as a measure of interest or activity around that reputable entity. Here are examples of claims in the form of text comments Flickr s Interestingness algorithm likely accounts for the rate of commenting activity targeted at evaluating the quality of photos. On Yahoo Local it s possible to give an establishment a full review with star ratings freeform comments and bar ratings for subfacets of a user s experience with the establishment . Or a user can simply leave a rating of 1 to 5 stars. This option encourages quick engagement with the site. It s