## 3 Materials and Methods
### Results
#### 3.4.2 Results Visualization  
The tweets were also presented on the cadastre map of the historic city center. In this way, it is possible to compare the land uses identified by the classifier against the land use category registered in the cadastre by the local municipality.  
The map of the historic center is shown in Figure 5 (on the left) with the classification of land uses according to the city's cadastre. On the map, each category of land use was associated with a color. Thus, the use of residential, commercial, industrial-office, institutional-governmental, and unbuilt land have the colors yellow, red, blue, light blue, and green, respectively. The second map in Figure 5 (on the right) shows the tweets labeled with the categories of land use. According to the information shown on the map, a large number of land uses corresponding to commercial, industrial, unbuilt land, and institutional-governmental were identified. However, a small number of tweets with the residential label is observed, although, according to the cadastre, a significant percentage of land uses in the historic center corresponds to residential. Therefore, there is no correspondence on the residential category between the cadastre and the automatic classification of land use.  
\begin{table}
\begin{tabular}{l l l l} \hline \hline
**Original Text** & **Latitude** & **Longitude** & **Label** \\ \hline Buenas noches Arequipat! (@ Zig Zag in & & \\ Arequipa) https://tco/SY97 QrTo9e https://tco/v4 UNcinljT0 & \(-\)16.39525055 & \(-\)71.53541831 & Commercial \\ \hline Amando conocer este pais [7]  en Plaza & & \\ de Armas de Arequipa https://tco/rBZ4 & \(-\)16.39869651 & \(-\)71.53693914 & Unbuilt land \\ Dmw0 il & & & \\ \hline \#Arequipa \#Arte \#Concierto de bienvenida & & & \\ en la inauguracion de la \#Exposicion & & & \\ \#Raices @ Centro De Las Artes De La Ucsp & & & \\ https://tco/f76n4 QdHks & & & \\ \hline Tarde de peliculas en casa \#amor & & & \\ \#dulchehogar \#movie time & & & \\ \hline Saliendo de la officina \#work en Galeria San & & & \\ Jose https://tco/BvkDpu2 zi6 & & & & \\ \hline \#Plus135: Que son las condiciones objetivas & & & \\ de punibilidad? https://tco/64 dol8 zoLI & & & \\ \hline \hline \end{tabular}
\end{table}
Table 8: Classification results with real data.  
In order to deepen the analysis of the inconsistencies revealed between the two methods, Figures 6 and 7 clearly show interesting differences. Color scale for land use is the same for both, as depicted in the legend. Figure 6 illustrates areas (light blue circle) labeled as residential in the cadastre, but identified as vacant land or institutional. On the other hand, Figure 7 shows a block (yellow) in which is located the Santa Catalina Convent, and it is cataloged as residential in the cadastre. However, tweets indicate the potential use as unbuilt or institutional-government land (religious is a subcategory within the last one). Multiple cases of inconsistency were detected when comparing cadastre and classifier outcome, many of which were later verified by a site visit. In general, the results provided by our approach were much more accurate than those registered in the cadastre.  
Figure 5: The image on the left shows the land use map of the historical center (cadastre); the image on the right shows the tweets labeled on the map by our approach.  
Figure 6: Example of inconsistency between the categorization of the cadastre and the result obtained by the classifier.