Keep it simple: Is deep learning good for linguistic smell detection?

Deep neural networks is a popular technique that has been applied successfully to domains such as image processing, sentiment analysis, speech recognition, and computational linguistic. Deep neural networks are machine learning algorithms that, in general, require a labeled set of positive and negative examples that are used to tune hyper-parameters and adjust model coefficients to learn a prediction function. Recently, deep neural networks have also been successfully applied to certain software engineering problem domains (e.g., bug prediction), however, results are shown to be outperformed by traditional machine learning approaches in other domains (e.g., recovering links between entries in a discussion forum). In this paper, we report our experience in building an automatic Linguistic Antipattern Detector (LAPD) using deep neural networks. We manually build and validate an oracle of around 1,700 instances and create binary classification models using traditional machine learning approaches and Convolutional Neural Networks. Our experience is that, considering the size of the oracle, the available hardware and software, as well as the theory to interpret results, deep neural networks are outperformed by traditional machine learning algorithms in terms of all evaluation metrics we used and resources (time and memory). Therefore, although deep learning is reported to produce results comparable and even superior to human experts for certain complex tasks, it does not seem to be a good fit for simple classification tasks like smell detection. Researchers and practitioners should be careful when selecting machine learning models for the problem at hand.