Chinese character radicals
In some cases the original semantic or phonological connection has become obscure, owing to changes in the meaning or pronunciation of the character over time.
The use of the English term radical is based on an analogy between the structure of Chinese characters and the inflection of words in European languages.
[2] In the earliest Chinese dictionaries, such as the Erya (3rd century BC), characters were grouped together in broad semantic categories.
In the 2nd century AD, the Han dynasty scholar Xu Shen organized his etymological dictionary Shuowen Jiezi by selecting 540 recurring graphic elements he called bù (部, "categories").
[3] Most were common semantic components, but they also included shared graphic elements such as a dot or horizontal stroke.
Some were even artificially extracted groups of strokes, termed "glyphs" by Serruys (1984, p. 657), which never had an independent existence other than being listed in Shuowen.
For example, characters containing 女 nǚ "female" or 木 mù "tree, wood" are often grouped together in the sections for those radicals.
After the writing system reform in mainland China, the traditional set of Kangxi radicals became unsuitable for indexing Simplified Chinese characters.
Sometimes, the radical may span more than one side, as in 園 = 囗 "enclosure" + 袁, or 街 = 行 "go, movement" + 圭.
[16] This is even truer of modern dictionaries, which cut radicals to less than half the number in Shuowen, at which point it becomes impossible to have enough to cover a semantic element of every character.
[9] The character simplification pursued in the People's Republic of China and elsewhere has modified a number of components, including those used as radicals.
Following the "section-header-and-stroke-count" method of Mei Yingzuo, characters are listed by their radical and then ordered by the number of strokes needed to write them.
Some modern computer dictionaries allow the user to draw characters with a mouse, stylus or finger, ideally tolerating a degree of imperfection, thus eliminating the problem of radical identification altogether.
In modern practice, radicals are primarily used as lexicographic tools and as learning aids when writing characters.
Modern dictionaries tend to eliminate these when it is possible to find some more widely used graphic element under which a character can be categorized.
Some use a system where characters are indexed under more than one radical and/or set of key elements to make it easier to find them.
[1]It is important to note that the concepts of semantic element and "section heading" (部首 bùshǒu) are different, and should be clearly distinguished.
The semantic element is parallel to the phonetic element in terms of the phonetic compound, while the section heading is a terminology of Chinese lexicography, which is a generic heading for the characters arranged in each section of a dictionary according to the system established by Xu Shen.
