Question #87b8f
1 Answer
Feb 16, 2018
A "baseline" of a particular value is selected at some point.
Explanation:
Defining a particular value may be the most difficult part, along with how to measure it objectively. Assuming that can be done, changes over time are always relative to some other value. Thus, a "baseline" year is selected, and the value(s) evaluated. Every subsequent measurement period is "indexed" to that baseline, showing relative changes instead of some absolute value.
This question looks more appropriate to Psychology or Statistics than Astronomy.
