Plain English Meaning
Every student gets taught the same things in the same order to the same standard, no matter which instructor they fly with that day.
Full Definition
A benefit of using lesson plans whereby every student in a course or program receives essentially the same instructional content, sequence, and standards regardless of which instructor delivers the lesson. It ensures consistent coverage of required material and consistent measurement of student progress across instructors and across time.
Context Anchor
Seen in lesson planning and flight instructor training, especially when lesson plans are used to keep instruction organized and consistent.
Derivation
Uniform comes from the Latin uniformis, meaning 'having one form.' So uniformity of instruction literally means teaching that has one form -- one consistent shape -- across instructors and students.
Why Pilots Care
It reduces variability in pilot and that could otherwise create gaps.