According to the characteristics of retrieval tools, basic retrieval can be divided into manual retrieval and computer retrieval. Manual retrieval includes: subject retrieval, name retrieval and number retrieval. According to the retrieval function, computer retrieval can be divided into: field retrieval, general logical combination retrieval, adjacent word retrieval and * * * storage retrieval, and logical combination retrieval between fields.
2. Expert search
Expert retrieval can be divided into: patent technology information retrieval, novelty retrieval, patent retrieval, infringement retrieval, patent legal status retrieval, family patent retrieval and technology introduction retrieval.