Suuruusosuus

Suuruusosuus is a Finnish term used in statistics, data analysis and related fields to describe the relative contribution of a particular magnitude within a total. It conveys the idea of a "magnitude share" or "size share," expressing how large a component is in relation to the whole.

Formally, for a set of nonnegative quantities x1, x2, ..., xn, the suuruusosuus of component i is si = xi / sum_j xj, provided that the total sum is greater than zero. The collection of si values forms a partition of unity, since sum_i si = 1. The measure is scale-invariant with respect to multiplication of all quantities by the same positive factor, but it depends on which components are included in the total.

Applications of suuruusosuus include describing market shares, budget allocations, dataset composition, and any scenario where it is useful to compare parts relative to the whole. It is typically expressed as a percentage in reporting.

Limitations and considerations include the requirement of nonnegative quantities; if all quantities are zero, the shares are undefined. Suuruusosuus does not capture the absolute magnitude, only the proportion. It can be influenced by the presence or absence of components and may mask large absolute differences if only proportions are considered. In some cases, alternative measures such as weights, normalized scores or log-transformed shares may be more informative.

Etymology: suuruus means magnitude or size, and osuus means share or proportion. See also proportional distribution, weighted share, relative frequency. Example: values 20, 30, 50 yield suuruusosuus 0.2, 0.3, 0.5 (20%, 30%, 50%).