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Chapter 6: How People Perform a First Gl... > SALIENCE ISSUES AT FIRST GLANCE - Pg. 224

How People Perform a First Glance Evaluation error rate. They would know one of the circles was black, but not which one. With pre-attentive processing, people can eas- ily detect some features. Interestingly, with pre- attentive processing, the number of distracters on the screen is not a factor. On the other hand, without pre-attentive processing, people have to do a serial scan of all of the objects, a very time- consuming and error-prone process as the number of distracters increase. Also, some of pre-attentive feature detections are asymmetric. For example, a sloped line in a sea of vertical lines can be de- tected pre-attentively. However, a vertical line in a sea of sloped lines cannot (Healey, Booth, & Enns, 1996; Treisman & Gormican, 1988). Box 2. Browsing in a bookstore One of my students told this story during a discussion on how people respond to texts. On each trip to the bookstore, my boyfriend keeps picking up the same nonfiction (biography) book. He'll browse the racks, pull out the book, do a check of its weight, flip the pages, and comment on the density of the paragraphs. I can tell he is interested in the topic and the book, but he mumbles "I'll never read this book," and returns it to the shelf. The boyfriend knows the type of book he reads and this particular book fails to fit those criteria during his few seconds looking at it. In the end, he decides he isn't willing to make the commitment to read the book, which fails in some way to be what he looks for in a book. He hadn't read any of the text and is interested in the topic, thus only the overall impression of the book can be driving him away. SALIENCE ISSUES AT FIRST GLANCE effort required--and people try to avoid tasks which require high mental effort. If the page does not appear to contain relevant information or it