A good bilingual law dictionary needs to take the users' expected language and professional competences into account. The lexicographers therefore must consider the following aspects: dictionary user research, dictionary typology, structure, and presentation of the relevant information. When making a law dictionary, the lexicographers attempt to present the information in such a way that the user is not burdened with excessive lexicographic information costs.
As pointed out in Nielsen 1994, law dictionaries can serve various functions. The traditional law dictionary with definitions of legal terms serves to help users understand the legal texts they read (a communicative function) or to acquire knowledge about legal matters independent of any text (a cognitive function) – such law dictionaries are usually monolingual. Bilingual law dictionaries may also serve a variety of functions. First, they may have entry words in one language and definitions in another language – these dictionaries give help to understand legal texts, usually written in a foreign language, and to acquire knowledge, usually about a foreign legal system. Second, bilingual law dictionaries with entry words in one language and equivalents in another language provide help to translate legal texts, into or from a foreign language, and sometimes also to produce legal texts, usually in a foreign language.
Unlike a law dictionary, which arranges and defines legal words and phrases individually and in alphabetical order, a legal terminology textbook arranges and defines legal words and phrases in groups and by topic. As a result, a student or other person interested in understanding an array of related legal words and phrases may prefer to use a legal terminology textbook instead.