> thinker can access about 220 ≈ 1 million possible items in the few seconds allotted Huh, no? No one is able to think about million items in a few seconds. T

> thinker can access about 220 ≈ 1 million possible items in the few seconds allotted Huh, no? No one is able to think about million items in a few seconds. The 20q thinking process involves bringing an incomplete set of abstract categories and asking a question that divides these categories into two halves (binary search). You don't even start from scratch, using previous experience (cache) to reuse whatever worked best the last time.