Data obtained by some form of experiment or measurement of the real world.
Used in Chap. 13: page 159
Also used in hcistats2e: Chap. 1: page 14; Chap. 10: pages 116, 122; Chap. 14: pages 181, 183
Used in Chap. 13: page 159
Also used in hcistats2e: Chap. 1: page 14; Chap. 10: pages 116, 122; Chap. 14: pages 181, 183