# Urban Land Use Survey Methods: A Discussion on Their Evolution
## 5 Discussion
One such silent discussion develops on the very _definition of the field_, with narrower or wider perspectives leading to different comprehensions of its boundaries. The narrow perspective, very much evident in contemporary readings, equates land use survey methodology with methods and techniques used in field inventories. The wider perspective includes all the theoretical and practical aspects of the whole process, which starts with the planning of a survey and concludes with the delivery of land use maps. Another discussion belonging here regards the _definition of the terms land use, urban use_, and _urban activity_. In many readings, especially the most contemporary ones, the use of these terms is problematic, as they are used interchangeably with their meaning varying according to context, while more often than not no (clear) definition is provided for each term. A recent article tried to shed some light on this discussion [4]; however, the field is still far from achieving widespread acceptance of the proposed terminology, as well as an understanding of the different cultural and scientific contexts that influence the use of these terms, especially between the United States and continental Europe. The classification of land uses also falls under the category of theoretical discussions. This appears to be, diachronically, the most heated debate, probably for two reasons: first, because land use classifications comprise a nodal part of planning legislation and, second, because classifications need to be revised periodically, since they are a product of their time, and to be adjusted to the specific objectives of each survey and study. The second major area of inquiry concerns the _methodological part_ of a land use survey. Based on the literature review, the discussions comprising this area can be organized under the following four topics, which correspond to the basic methodological steps of a land use survey. (a) _Planning of the survey_: this topic includes all discussions on the objectives, the resources, the timeframes, and the expected outcomes of a land use survey, as well as discussions on the identification of the exact land use properties that need to be surveyed and in relation to the practical obstacles in their collection. (b) _Preparation of field inventories_: this topic includes discussions on the technical and administrative preparative tasks required for a smooth and productive survey, which range from the production of base maps to training the surveyors. (c) _Conducting field inventories_: this includes all discussions on the methods and techniques utilized in field inventories, such as the use of field listing forms, the use of digital applications, the rules followed for the required simplification of building geometry, or the techniques used in ascertaining the use of non-accessible buildings. (d) _Processing of records and representation of land uses_: this topic is dominated by discussions on the application of the principles of cartography and thematic mapping in the production of land use maps; recent discussions on GISs and databases could also be included here. In addition, there are a number of discussions that constitute the _periphery of the field_. These discussions establish connections with other fields of knowledge, contribute to wider debates, or link land use surveys to other phases of the planning process. The identification and the grouping of these discussions in topics fall out of the scope of the present article since the literature review did not focus on these peripheral discussions. A few indicative examples of the latter have already been mentioned, such as discussions linking land use surveys to racial segregation or considerations of the divergence between theory and practice. The present study on the evolution of land use survey methods is also a discussion located in the periphery.