Most works that are published professionally (including popular newspapers and magazines, as well as scholarly journals and trade magazines) will have been edited carefully. These sources will generally avoid errors of grammar, punctuation, and spelling. Web sites sponsored by professional organizations, too, will generally avoid these kinds of errors. Personal Web sites, however, are unlikely to have been professionally edited and fact-checked. If a Web site is riddled with errors, be very careful to double-check any information you take from that site.