How are words sorted in a Chinese dictionary?
For dictionaries in languages based on the Roman alphabet, the order of words is very simple, and derives on the alphabetical order that has been defined for more than 2,000 years. In particular, the order in Greek letters was alpha, beta, gamma (thus the name alphabet).
In Chinese though, words are characters and are defined by strokes and not by a combination of characters from an alphabet, so it has proven much more difficult to order them for easy retrieval.
Historically, there has been several types of dictionaries:
Semantic order, where words were organized in semantic categories, which made the search very difficult
Graphical order, where the organization is based on a combination or radicals and strokes (see below)
Phonetic order, where the order is based on rimes and tones, which is also difficult for people not familiar with rimes
Pinyin order, based on the pinyin romanisation of Chinese words, which is very easy for foreigners and also easy to learn for Chinese native speakers
Nowadays, most English-Chinese dictionaries employ the pinyin order.
Many Chinese-only dictionaries employ the radical and stroke method, where characters are first grouped by their primary radical, such as 亻(person) or 山 (mountain), then by the number of strokes added to the radical to form the full character. For example 妈 (“mother”) is sorted as a six-stroke character under the three-stroke primary radical 女.
It’s nice to have a combination of both, so:
If you know how to pronounce a word but don’t know how it’s written, you can use the pinyin order
If this is a new word you have seen in a book but don’t know how to pronounce, you can use the stroke method.
Finally, computer or mobile devices now enable search by strokes. The user only needs to draw or type the first strokes of the character and is presented with a choice of full characters. Unfortunately, this can only be used if you know the order of strokes in a character!