software to be installed on the user's computer; they only have to have JavaScript enabled for the researcher to collect data from the webpage. Mouse tracking using JavaScript has been deployed on high-traffic websites such as search engines to collect mouse movement data without affecting the user's computer performance. Data Current mouse tracking tools provide a variety of data including the location of the mouse (in terms of pixels), time stamps, any time the mouse hovers on a link of interest, mouse clicks, time spent in areas of interest, and duration of hovers. Additionally, some tracking tools provide more high level analyses, such as heat maps and playbacks which can retrace the mouse's trajectory. An example of an output log is below: 141.84.8.77 2006-09-01,18:44:07 serverdata 8 141.84.8.77 2006-09-01,19:44:08 8 load size=1047x529 141.84.8.77 2006-09-01,19:44:08 8 mousemove coord=283,2 141.84.8.77 2006-09-01,19:44:09 8 mousemove coord=257,125 141.84.8.77 2006-09-01,19:44:10 8 mouseover coord=247,152 name=f dom=abae 141.84.8.77 2006-09-01,19:44:13 8 select radio id=lgr value=lr%3Dlang_de dom=abaecabaac 141.84.8.77 2006-09-01,19:44:16 8 click coord=374,187 name=q dom=abaecaabb 141.84.8.77 2006-09-01,19:44:17 8 keyPress key=H 141.84.8.77 2006-09-01,19:44:17 8 keypress key=a Applications Usability testing Mouse movements can be used to infer a user's intent and focus while browsing a website. By using mouse movements in usability testing, researchers can determine if users are confused, if their expectations are met, where their attention is focused, and much additional information. This tool can be especially beneficial in conjunction with other techniques used in usability testing, such as think aloud procedures, as this information can lead to a better mouse movement model. Real-time website adaptation Tracking mouse movements can be used to adapt interfaces in real time based on respondents' interests. Researchers can use information, such as where respondents hold the mouse for an extended period of time and the trajectory of the mouse, to assess their level of interest in that object. The knowledge gained from this can be used to re-sort search criteria based on individual relevancy and suggest other objects, products, or information that might be of interest to the user. Web design and evaluation Mouse tracking allows Web developers to view the behaviors of actual users in their natural browsing environment instead of in a laboratory. By tracking where the mouse is located, designers can evaluate the ease of use of their Websites. Specifically, they can see how difficult it is for users to find and use certain features, such as scroll bars or dropdown menus, or