It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
Booth, Wayne, Gregory Colomb, and Joseph Williams. (2008). Moving from identifying a topic to developing a research question. The Craft of Research, 3rd ed. Chicago: University of Chicago Press, p. 45-48.