Averages and Standard Deviations, but Skewness and Kurtosis?

Solution 1:

The division between countable and uncountable nouns is not so strict and arbitrary for abstract nouns as you seem to have learned. When an abstract noun refers to a specific measurable quantity or quality, it is often possible to pluralize it, even if the noun normally is not used in the plural form.

"Volatilities" is not an impossible form; you can see it used in a 2004 book by David Ruppert:

The implied volatilities vary among themselves.

(Statistics and Finance: An Introduction, p. 280)

Similarly, plural forms of "-ness" nouns, such as "skewnesses", can be used in this kind of context, as shown by this quote from "Robustness in ANOVA", by Rand Wilcox:

If the skewnesses corresponding to the two groups are identical,

(Applied Analysis of Variance in Behavioral Science, 1993, edited by Lynne Edwards, p. 350)

That said, "informations" does sound strange to me even in this context. (I think it's because "information", unlike "volatility" and "skewness", is not treated in ordinary speech as a noun that refers to a quality of something.)

If pluralized, "kurtosis" would most likely turn into "kurtoses" /kəɹˈtoʊsiːz/ rather than "kurtosises". Nouns ending in -sis, which mainly come from Greek, generally pluralize by replacing -sis /sɪs/ with -ses /siːz/.

You can avoid the use of any plural forms by using a phrasing like "The table displays the average, standard deviation, skewness, kurtosis, and Fisher information for each state." This is how I would recommend writing a sentence to explain a table like this.

Solution 2:

Value is a countable noun:

a numerical quantity that is assigned or is determined by calculation or measurement

(Merriam Webster)

And that is what all of these uncountable numbers actually are!

So, in order to avoid vocabulary bloat, append the plural values to the class name, andyou get skewness values, kurtosis values, Fisher values, volatility values. This should be your default way to name a group of similar uncountable measurements.