expectationally

Expectationally is an adverb form of the adjective expectational, describing an action performed with regard to or in terms of expectation. The root is expectational, derived from expectation, with the typical adverbial suffix -ly. The term is not common in general English and is mainly encountered in specialized writings, especially in probability theory, statistics, and some branches of logic, where emphasis on the notion of an expectation or expected value is important.

In use, expectationally signals that the operation or conclusion is framed through the concept of expectation rather than through observed outcomes alone. For example, sentences in technical contexts might read that results are derived expectationally by computing the expected value under the given distribution, or that a proof proceeds expectationally by appealing to the properties of the expectation operator.

Alternative forms and related terms include expectational (the adjective) and expectation (the noun). In many contexts, however, more common expressions such as in expectation, as expected, or expectedly are preferred for clarity. The adverb expectationally tends to appear mainly in dense or formal writing where emphasis on theoretical constructs of expectation is desired.

Because it is relatively rare outside technical writing, expectationally can be obscure to general readers. When clarity is the aim, replacing it with more common phrasing that references expectation or expected values is usually advisable.