Tapping the plus sign will reveal more information about the photo or an interactive feature.

The play icon signifies video, audio, or animations that elaborate on a point discussed in the text.

The clapboard icon denotes areas where the author has shared behind-the-scenes facts and stories from the making of this book, Duarte, Inc., and life.

The Presentation Form™ is used as an analysis tool throughout the book and is visually expressed as a sparkline (a term developed by Edward Tufte). Touch the Presentation Form to expand it and reveal an interactive analysis of the presentation. Some Presentation Forms come with additional features, like transcripts and audio.

The light blue pages at the end of each chapter contain a quiz, which covers the information discussed in the previous section. To answer the questions, select one of the multiple-choice options. Then, touch “Check Answers” to see if you’re correct. For each correct answer, the selection will be highlighted in green. For each incorrect answer, your selection will be highlighted in red and a green border will appear around the correct option. The quiz will tally the final score and calculate your percentage. “Try Again” will clear all the answers.