According to the "MLA Handbook for Writers of Research Papers" (7th edition), all information taken from outside sources must be cited in your research paper, including words and ideas from formal interviews and informal, private conversations. Proper citation of such information helps eliminate plagiarism, which can have long-reaching, negative consequences.
In MLA style, a conversation is treated as a formal interview. That means the signal phrase or citation gives the speaker's name. In a citation, the name appears within parentheses at the end of the borrowed words or ideas but before the end punctuation: (Smith). Alternatively, you may use the text to indicate the source, such as "According to Judy Smith." Because the source does not have a printed form, no page number is included.
Works Cited Entry
The entry on the Works Cited page helps the reader find more information about the sources you use in your paper. Although a conversation is not something your reader can look up, you still need a Works Cited entry to indicate where the ideas came from. Begin the entry with the speaker's last name, a comma, and the first name, followed by a period. Explain the type of communication with a phrase such as "Personal conversation" or "Personal interview," followed by a period. The date appears at the end of the entry in day-month-year order with no punctuation between, ending with a period. An entry might look like this:
Smith, Judy. Personal interview. 3 March 2013.