f-ratio
UK[ˈef ˌreɪ.ʃi.əʊ]US[ˈef ˌreɪ.ʃoʊ]
n
In statistics, a value obtained by dividing two mean squares, used especially in analysis of variance to test hypotheses.
n
In astronomy, the focal ratio of an optical system, such as a telescope.
Morpheme Breakdown
f
ratio
f
symbol
ratio
mathematical term
Etymology
The term 'f-ratio' is a modern compound formed within specialized scientific English. Its first element is the letter 'f', employed as a symbolic abbreviation. In statistics, 'f' honors Sir Ronald Fisher, who pioneered the analysis of variance method, thus the 'f' denotes the test statistic bearing his name. In optics, 'f' stands for 'focal', designating the focal length. The second element, 'ratio', comes directly from Latin 'ratio', meaning a calculation or proportion, which entered English via French in the 16th century. The compound logically denotes a specific proportional value (a ratio) associated with the concept symbolized by 'f', creating a concise technical term for professional discourse.
Analysis
Structure: f (symbol) + ratio (mathematical term)
f: A Latin letter used as a symbol, named 'ef'. In this context, it stands for a specific statistical function or for 'focal'.
ratio: From Latin 'ratio' (reckoning, calculation, reason). In English, it functions as a noun meaning the quantitative relation between two amounts.
Examples
A high f-ratio in the ANOVA test indicates a significant difference between group means.
Astrophotographers often prefer a telescope with a low f-ratio for capturing brighter images of deep-sky objects.
The researcher calculated the f-ratio to determine if the variance between the datasets was statistically meaningful.