**Traditionally thought to be 7 things, more recent studies suggest 4.** Working memory has been thought to hold ~5 to 9 things. This "Magic of the Number 7" extends to several other things. People can generally hold about seven different "bucketing groups" in their **working memory** for things like "pitch frequency" (I'll play you a tone, you tell me which number it corresponds with, we start to fail when the number of tones goes above 7), or 7 levels of taste for things like saltiness or sweetness. Famously, it's why phone numbers have 7 digits. It's also why, in the realm of [[Systems Engineering]], we usually decompose systems into whatever number of levels is needed such that no level contains (much) more than 7 parts. (see [[Systems Decomposition Rule of 7]]) According to [[The Organized Mind]], more recent studies suggest the number should be more like "4". # The Good News! The good news is, for most decisions 7 things would be more than enough to cover the [[Optimum Level of Information]]. The trick is having the **right** things to focus on. **** # More ## Source - [[The Organized Mind]] - [[The Tipping Point]] - [[MIT 16 842 - Fundamentals of Systems Engineering M]] ## Related - [[Memories are Associative]] - [[Less, but Better]] - [[Groups of 150 - Dunbar's Number]] - [[Systems Decomposition Rule of 7]] - [[Optimum Level of Information]]