Summary of 'Deep Work' by Cal Newport. (2 Summaries in 1: In-Depth Summary and Bonus 2-Page PDF.)

Deliberate practice is a complex topic. In a nutshell, it is practice designed to improve a specific skill using intense focus, repetition and continuous feedback. Deliberate practice is cognitively demanding, requires intense concentration and cannot be done with distraction. As Ericsson explains, "Diffused attention is almost antithetical to

K. Anders Ericsson found that experts' capacity for deliberate practice was limited to about four hours per day, due to both cognitive and physical fatigue. Like deliberate practice, deep work is also cognitively demanding, so it stands to reason that both share similar limits.

Sophie Leroy, a business professor at the University of Minnesota, discovered in experiments that when people switch tasks, attention doesn't immediately follow. Part of the attention remains stuck on the prior task, resulting in worse performance on the next task. She called this effect attention residue, which becomes stronger in these instances:

When time is limited, shallow work and time-wasters will be the first to get squeezed out, as Basecamp experienced when it moved to a four-day workweek.

Individuals work in these chambers for 90 minutes at a time, followed by a 90-minute break. This three-hour cycle is repeated two or three times each day.

The need for a shutdown ritual stems from the Zeigarnik effect, which is the tendency of incomplete tasks to continuously engage our thoughts. At the end of the day, your mind will continue to engage with these incomplete tasks, preventing mental rest. Fortunately, you don't need to complete all tasks to avoid this outcome. Experiments by Roy Baume

6 Strategies To Reduce Shallow Work Quantify the depth of every activity Create a shallow work budget Schedule your entire day Use fixed-schedule productivity Learn how to say "no" Manage email senders

Professorial approach to emails The last approach is based on the behavior of many professors; they simply do not respond to emails unless the sender convinces them that a reply is worth the time and effort. The professorial approach calls for ignoring the email for a few reasons: The message is unclear or difficult to respond to The subject is uni

Based on this research, Dijksterhuis and his collaborators proposed unconscious thought theory, which states that the disengaged mind unconsciously works on solving previously presented problems.