A Comparative Evaluation of Online Geocoding Services in China

Online geocoding services are the most common technique for transforming non-spatial into spatial information. The increasing number of online geocoding services, however make it difficult for requestors to choose a better service. There are two aims in this paper: (1) to provide guidance for service requestors when selecting the most suitable service; (2) to discover the defects of online geocoding services, thus providing a basis for further improvements. In this paper, a comparative evaluation of geocoding quality was conducted among the most four popular online geocoding services: Baidu, Amap, Sougou, and Tencent. Four types of address data associated with basic public necessities were used as test data, and three metrics for geocoding quality: match rate, positional accuracy and similarity, were calculated to evaluate the quality of these four online geocoding services. The following conclusions were drawn: (1) online geocoding service quality mainly depends on the quality of the reference database; (2) Amap produced the highest match rate and lowest positional accuracy; (3) Overall, the Tencent map service performs the best, and produced more complete address data with higher data quality.