A bit of bedtime reading is a fairly common practice, and researchers examined whether changes in reading technology could impact sleep quality. They recruited a sample of 12 healthy adults to sleep in a sleep lab on two different days. In random order, participants read, for 30 minutes, a print book on one night and a light-emitting e-reader on the other night. Scalp electrodes used to measure how long (in minutes) it took participants to reach a deep sleep stage. On average, the subjects took 12.3 minutes longer to reach deep sleep when they read with the e-reader than when they read with the book. 14 (a) What are the individuals, the treatments, and the response variable in this experiment?
(b) What is the design of this experiment?
(c) Sleeping in an unfamiliar environment can create a sleep disturbance called the first night effect. Explain why it is important to select the print-book and e-reader nights in random order for each participant.