Systemic errors
I once made a beautiful study device. It was for Greek. It was a custom-copied and bound compilation of the noun and verb charts needed to accurately perform translations.
I worked in the university print shop, so I had the resources to make it.
It was beautiful. Compact, efficient and practical. A more synthesized and useful version than the actual book we used in class.
But it had an error. I had mistakenly put the wrong suffix on one of the charts.
No matter how beautiful the system-efficient and effortful-if it's wrong, it's wrong. No system corrects an error within the system.