What does scale exactly mean? I am not so familiar with statistical concepts. I am preparing a questionnaire to measure underlying constructs that affect pedestrian's road crossing behavior. However, I came across this term called "scale". Earlier I used to think that scale simply means measurement scale (e.g. nominal, ordinal, numerical etc.). But I have seen people using the term "scale construction".
Could someone me tell me what it means by constructing a scale (as asked in this question: https://www.researchgate.net/post/What_is_the_fundamental_procedure_for_Scale_construction)?
Update: I have updated the question to be more clear and precise.
 A: This word has many meanings, e.g.


*

*measurement scale (nominal, ordinal, etc.) is a classification of variables in statistics in terms of mathematical operations that can be applied to them,

*in probability and statistics scaling factor of probability distribution, so $Y = bX$ is a random variable defined in terms of random variable $X$ scaled by the $b$,

*what follows, we have location-scale distributions with location $a$ and scale $b$ parameters, $Y = a + bX$ (e.g. mean and variance in normal distribution) that lead to transforming probability density function to $f_Y = f_X(\tfrac{X-a}{b})\,/\,b$, and cumulative distribution function to $F_Y = F_X(\tfrac{X-a}{b})$,

*in psychometrics people often call the questionnaire as "scale", e.g. Wechsler Adult Intelligence Scale is one of the most popular IQ tests.


What exactly it means depends on context.
A: A guess:
"scale" in PCA could arise form question "should we standardize variables before running PCA?". 
The answer is "Yes", because if we do not, a scale of variable affects results. If, for example, one of variables is in centimeters and we change it's scale to meters, we would get completely different results in PCA.
Also if scale of one of the variables is from 0 to 1 and another from 0 do 1000, the later would have greater impact on PCA results.
So, my guess is that scale here means "unit", "range", "extent" etc.
Plus, R function that performs standardization is... scale :)
