An hybrid architecture is one where different moduels or layers use different kinds of AI technolgies. For example, we might use a random forest to perform low-level classification (say of human activity in a care setting), and then use these classes in a hand-crafted rule-based system (say "if suspected fall, alert warden").
Used in Chap. 6: pages 84, 86; Chap. 7: page 98; Chap. 12: page 181; Chap. 18: page 283
Example of a hybrid architecture