A reading error is defined as the selection of the incorrect word in a written text, that is, the word not intended by the text's author. A significant concern is how extensively such faulty choices impact the overall reading of the text. The most common types of reading errors include misspellings, grammar mistakes, and paraphrases. Other types include hyperlinks which lead to incorrect pages, images that don't correspond to the text, and material added by a user viewing the text on a computer screen. Misspellings are the most common type of reading error and account for nearly all reading errors made by college students. They often involve the transposition of two or more letters, but other changes also occur with greater frequency than others. For example, the word "its" is incorrectly written as "it's" about half the time. Other commonly misprinted words include "there," "their," and "they're." Also common are words that have been substituted because they sound alike or differ only in spelling (e.g., "affect/effect"). Many misspellings can be corrected by simply looking up the word in a dictionary or thesaurus. Often, however, even when corrected, these words remain problematic because they violate readers' expectations about how letters are ordered. For example, "cafeteria-style dining" violates readers' expectations about what comes next after "fountain dining."