Identifying Drone Web Sites in Multiple Countries and Languages with a Single Model

A text-based, bag-of-words, model was developed to identify drone company websites for multiple European countries in different languages. A collection of Spanish drone and non-drone websites was used for initial model development. Various classification methods were compared. Supervised logistic regression (L2-norm) performed best with an accuracy of 87% on the unseen test set. The accuracy of the later model improved to 88% when it was trained on texts in which all Spanish words were translated into English. Retraining the model on texts in which all typical Spanish words, such as names of cities and regions, and words indicative for specific periods in time, such as the months of the year and days of the week, were removed did not affect the overall performance of the model and made it more generally applicable. Applying the cleaned, completely English word-based, model to a collection of Irish and Italian drone and non-drone websites revealed, after manual inspection, that it was able to detect drone websites in those countries with an accuracy of 82 and 86%, respectively. The classification of Italian texts required the creation of a translation list in which all 1560 English word-based features in the model were translated to their Italian analogs. Because the model had a very high recall, 93, 100, and 97% on Spanish, Irish and Italian drone websites respectively, it was particularly well suited to select potential drone websites in large collections of websites.