Comparison

Sponsorship the way you would do it

A comparison is an evaluation of similarities and differences - described by Gregory Bateson in his book Mind and Nature as the two quanta of experience.

In computer programming

In computer programming, when one compares the two values x and y, a negative number often indicates x < y, zero x == y and a postive number x > y. Even when two values are not integers, e.g. literal strings, this convention is largely adopted. For example, strcmp returns -1, 0, or 1 according to the lexigraphical order, and qsort expects the comparison function to return values according to this convention. This is because it is efficient to do the subtraction x - y resulting in the directional signs above. In sorting algorithms, the efficiency of comparison code is critical since it is one of the major factors of sorting performance.

Sometimes, particularly in object-oriented programming, the comparison raises questions of datatypes and inheritance, equality and identity. It is often necessary to distinguish between:

two objects with different datatypes both related to another datatype, e.g. an orange and a lemon, both being citrus fruit
two different objects of the same type, e.g. two hands
two objects being equal but distinct, e.g. two $10 banknotes
two different references to the same object, e.g. two nicknames for the same person

Sameness and difference can be relative or graduated as well as absolute, particularly in fuzzy logic, artificial intelligence, signal processing, lossy data compression and pattern recognition.

See also: regular expression

In grammar

Comparison, in grammar, is a property of adjectives and adverbs in most languages; it describes systems that distinguish the degree to which the modifier modifies its complement.

English, due to the complex etymology of its lexicon, has two parallel systems of comparison. One involves the suffixes -er (the "comparative") and -est (the "superlative"). These inflections are of Indo-European origin, and are cognate with the Latin suffixes -ior and -issimus. These inflections are typically added to shorter words, words of Anglo-Saxon origin, and borrowed words that have been fully assimilated into the English vocabulary. Usually the words that take these inflections have fewer than three syllables. This system contains a number of irregular forms, some of which, like good, better, best, contain suppletive forms. These irregular forms include:

good        better       best

well        better       best

bad         worse        worst

far         farther      farthest

far         further      furthest

little      less(er)     least (also has regular forms)

many more most

The second system of comparison in English appends the grammatical particles more and most, themselves the irregular comparatives of many, to the adjective or adverb being modified. This series can be compared to a system containing the diminutives less and least. This system is most commonly used with words of French or Latin derivation; adjectives and adverbs formed with suffixes other than -ly (e.g. beautiful); and with longer, technical, or infrequently used words. Knowing which words fall into which system is a highly idiomatic issue in English syntax. Some words require the suffixing system: e.g. taller is required; *more tall is not idiomatic English. Some words (e.g. difficult) require more and most. Some words (e.g. polite) can be used with either system; curiously, while polite can go either way, the derived word impolite requires more and most.

A perennial issue in English usage involves the comparison of so called "absolute" adjectives, the use of terms of comparison with words that in logic are not thought to admit of comparison. There are, of course, many adjectives that admit of no comparison, chiefly because the qualities they name are either present or absent; nothing is *more Cretaceous or *more igneous. The issue arises with words such as perfect, which according to the prescriptivists is another quality that does not admit of comparison; either something is perfect or it is not. Since true perfection is unachievable in the sublunary sphere, people like the drafters of the Constitution of the United States are constantly saying things like form a more perfect union; what they mean, of course, is more nearly perfect, and this is what the usage prescriptivists think they should have written. Since good writers and important leaders have used the contested form, the prescriptivists are bucking a well established usage here; in practice, the contested form is understood without error.