6- Chris Ki

      The book says the definition of “mental model” is what we believe to be true, generally based on our experiences; for users to feel good about using an application, and make them feel as if they really do understand the features that they’re using. In case of YouTube, mental model would be something like users expecting to get everything done just by clicking at icons and buttons. In contrast, all those simple ways of using features were made possible by the programmers writing complicated programs and command lines.

      Mental model would be more like inserting pictures when users are using PowerPoint or Word. That can be done just by simply clicking the picture icon from the menu bar, and then navigating through the folders to choose the right picture. However, if you are to upload a picture in most of web forums, you have to type something like a command line that looks like [ img ]link address of the picture[ /img ] on the post (implementation model). Implementation model isn’t really user-friendly.