# TRLs are not monotonic When you’re attempting to move from one TRL to another, you could discover that you need to go back down several levels and fix something. * At TRL 2, you could realize that you don’t understand the phenomenon well enough and the inventive description you’ve created is unconstrained ( [[Describing an effect in an inventive manner is important for separating invention and discovery]] ) * At TRL 3, you could discover that the proof of concept just doesn’t work and need to go back to TRL 1 * At TRL4, you could discover that the core piece of the system you proved out in TRL 3 was actually not the crux Etc This is actually another formulation of the thesis in [[narayanamurtiCyclesInventionDiscovery2016]] ### Related * [[Phenomena-based cycles]] <!-- #evergreen --> [Web URL for this note](http://notes.benjaminreinhardt.com/TRLs+are+not+monotonic) [Comment on this note](http://via.hypothes.is/http://notes.benjaminreinhardt.com/TRLs+are+not+monotonic)