Anomaly Detection on Natural Language Processing to Improve Predictions on Tourist Preferences

Jorge Meira,João Carneiro,Amparo Alonso-Betanzos,Paulo Novais,Goreti Marreiros,Verónica Bolón-Canedo

doi:10.3390/electronics11050779

Jorge Meira, João Carneiro + Show 4 more

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https://doi.org/10.3390/electronics11050779

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Abstract

Argumentation-based dialogue models have shown to be appropriate for decision contexts in which it is intended to overcome the lack of interaction between decision-makers, either because they are dispersed, they are too many, or they are simply not even known. However, to support decision processes with argumentation-based dialogue models, it is necessary to have knowledge of certain aspects that are specific to each decision-maker, such as preferences, interests, and limitations, among others. Failure to obtain this knowledge could ruin the model’s success. In this work, we sought to facilitate the information acquisition process by studying strategies to automatically predict the tourists’ preferences (ratings) in relation to points of interest based on their reviews. We explored different Machine Learning methods to predict users’ ratings. We used Natural Language Processing strategies to predict whether a review is positive or negative and the rating assigned by users on a scale of 1 to 5. We then applied supervised methods such as Logistic Regression, Random Forest, Decision Trees, K-Nearest Neighbors, and Recurrent Neural Networks to determine whether a tourist likes/dislikes a given point of interest. We also used a distinctive approach in this field through unsupervised techniques for anomaly detection problems. The goal was to improve the supervised model in identifying only those tourists who truly like or dislike a particular point of interest, in which the main objective is not to identify everyone, but fundamentally not to fail those who are identified in those conditions. The experiments carried out showed that the developed models could predict with high accuracy whether a review is positive or negative but have some difficulty in accurately predicting the rating assigned by users. Unsupervised method Local Outlier Factor improved the results, reducing Logistic Regression false positives with an associated cost of increasing false negatives.

Highlights

IntroductionArgumentation-based dialogue models are extremely useful in contexts where a group of agents is intended to find solutions for complex decision problems using negotiation and deliberation mechanisms [1–3]
Some of them are overlapped with users with positive sentiments, which means that improvements in reducing false positives are possible, they come with the cost of increasing false negatives
The method consisted in using Machine Learning algorithms and Natural Language Processing techniques on reviews that tourists posted on TripAdvisor® to predict their assigned ratings

Summary

Introduction

Argumentation-based dialogue models are extremely useful in contexts where a group of agents is intended to find solutions for complex decision problems using negotiation and deliberation mechanisms [1–3] They allow human decision-makers to understand the reasons that led to a given decision (enhancing the acceptance of decisions) and to define mechanisms for intelligent explanations [4,5]. These models receive the decision-makers’ preferences as input (for instance, regarding criteria and alternatives), which are typically used to model the agents that represent them [6] Obtaining these preferences is not a simple process: first, in the contemporary and highly dynamic world in which we live, it is less and less comfortable for decision-makers to answer questionnaires and, second, it is sometimes difficult to express preferences through questionnaires [7,8]. Strategies that aim to automatically identify the users’

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