Accuracy
Learning STRIPS Action Models with Classical Planning
Aineto, Diego, Jiménez, Sergio, Onaindia, Eva
This paper presents a novel approach for learning STRIPS action models from examples that compiles this inductive learning task into a classical planning task. Interestingly, the compilation approach is flexible to different amounts of available input knowledge; the learning examples can range from a set of plans (with their corresponding initial and final states) to just a pair of initial and final states (no intermediate action or state is given). Moreover, the compilation accepts partially specified action models and it can be used to validate whether the observation of a plan execution follows a given STRIPS action model, even if this model is not fully specified.
Fairness in Recommendation Ranking through Pairwise Comparisons
Beutel, Alex, Chen, Jilin, Doshi, Tulsee, Qian, Hai, Wei, Li, Wu, Yi, Heldt, Lukasz, Zhao, Zhe, Hong, Lichan, Chi, Ed H., Goodrow, Cristos
Recommender systems are one of the most pervasive applications of machine learning in industry, with many services using them to match users to products or information. As such it is important to ask: what are the possible fairness risks, how can we quantify them, and how should we address them? In this paper we offer a set of novel metrics for evaluating algorithmic fairness concerns in recommender systems. In particular we show how measuring fairness based on pairwise comparisons from randomized experiments provides a tractable means to reason about fairness in rankings from recommender systems. Building on this metric, we offer a new regularizer to encourage improving this metric during model training and thus improve fairness in the resulting rankings. We apply this pairwise regularization to a large-scale, production recommender system and show that we are able to significantly improve the system's pairwise fairness.
MaMaDroid: Detecting Android Malware by Building Markov Chains of Behavioral Models (Extended Version)
Onwuzurike, Lucky, Mariconti, Enrico, Andriotis, Panagiotis, De Cristofaro, Emiliano, Ross, Gordon, Stringhini, Gianluca
As Android has become increasingly popular, so has malware targeting it, thus pushing the research community to propose different detection techniques. However, the constant evolution of the Android ecosystem, and of malware itself, makes it hard to design robust tools that can operate for long periods of time without the need for modifications or costly re-training. Aiming to address this issue, we set to detect malware from a behavioral point of view, modeled as the sequence of abstracted API calls. We introduce MaMaDroid, a static-analysis based system that abstracts the API calls performed by an app to their class, package, or family, and builds a model from their sequences obtained from the call graph of an app as Markov chains. This ensures that the model is more resilient to API changes and the features set is of manageable size. We evaluate MaMaDroid using a dataset of 8.5K benign and 35.5K malicious apps collected over a period of six years, showing that it effectively detects malware (with up to 0.99 F-measure) and keeps its detection capabilities for long periods of time (up to 0.87 F-measure two years after training). We also show that MaMaDroid remarkably outperforms DroidAPIMiner, a state-of-the-art detection system that relies on the frequency of (raw) API calls. Aiming to assess whether MaMaDroid's effectiveness mainly stems from the API abstraction or from the sequencing modeling, we also evaluate a variant of it that uses frequency (instead of sequences), of abstracted API calls. We find that it is not as accurate, failing to capture maliciousness when trained on malware samples that include API calls that are equally or more frequently used by benign apps.
Catching Bugs Without Really Trying
Finding and fixing bugs is critical to delivering quality software. One-time new bugs are often introduced into a system when changes are uploaded to a software repository. Changes may be due to adding new features or possibly correcting existing bugs. Mozilla is planning on taking advantage of research being done by Ubisoft using artificial intelligence (AI) and machine learning (ML) to automatically catch software bugs when source code is committed to a software repository. The software is called CLEVER for Combining Levels of Bug Prevention and Resolution techniques.
What is Predictive Model Performance Evaluation DIMENSIONLESS TECHNOLOGIES PVT.LTD.
Evaluation metrics have a correlation with machine learning tasks. The tasks of classification, regression, ranking, clustering, topic modelling, etc, all have different metrics. Some metrics, such as precision, recall, are of use for multiple tasks. Classification, regression, and ranking are examples of supervised learning, which comprises a majority of machine learning applications. In this blog, we'll be focusing on the metrics for supervised learning modules.
Continuous Integration of Machine Learning Models with ease.ml/ci: Towards a Rigorous Yet Practical Treatment
Renggli, Cedric, Karlaš, Bojan, Ding, Bolin, Liu, Feng, Schawinski, Kevin, Wu, Wentao, Zhang, Ce
Continuous integration is an indispensable step of modern software engineering practices to systematically manage the life cycles of system development. Developing a machine learning model is no difference - it is an engineering process with a life cycle, including design, implementation, tuning, testing, and deployment. However, most, if not all, existing continuous integration engines do not support machine learning as first-class citizens. In this paper, we present ease.ml/ci, to our best knowledge, the first continuous integration system for machine learning. The challenge of building ease.ml/ci is to provide rigorous guarantees, e.g., single accuracy point error tolerance with 0.999 reliability, with a practical amount of labeling effort, e.g., 2K labels per test. We design a domain specific language that allows users to specify integration conditions with reliability constraints, and develop simple novel optimizations that can lower the number of labels required by up to two orders of magnitude for test conditions popularly used in real production systems.
On the usage of the probability integral transform to reduce the complexity of multi-way fuzzy decision trees in Big Data classification problems
Elkano, Mikel, Uriz, Mikel, Bustince, Humberto, Galar, Mikel
We present a new distributed fuzzy partitioning method to reduce the complexity of multi-way fuzzy decision trees in Big Data classification problems. The proposed algorithm builds a fixed number of fuzzy sets for all variables and adjusts their shape and position to the real distribution of training data. A two-step process is applied : 1) transformation of the original distribution into a standard uniform distribution by means of the probability integral transform. Since the original distribution is generally unknown, the cumulative distribution function is approximated by computing the q-quantiles of the training set; 2) construction of a Ruspini strong fuzzy partition in the transformed attribute space using a fixed number of equally distributed triangular membership functions. Despite the aforementioned transformation, the definition of every fuzzy set in the original space can be recovered by applying the inverse cumulative distribution function (also known as quantile function). The experimental results reveal that the proposed methodology allows the state-of-the-art multi-way fuzzy decision tree (FMDT) induction algorithm to maintain classification accuracy with up to 6 million fewer leaves.
Machine Learning Series Day 3 (Naive Bayes) – Becoming Human: Artificial Intelligence Magazine
Intuitively, the idea of a Naive Bayes is how you probably approach life. Like all my articles, I believe that a simple and intuitive understanding of a model should be understood first before diving into the mathematics and practical jargon. Let's say you're responsible for Thanksgiving dinner. You have cooked Thanksgiving dinner for the last ten years. Within those ten years, you have prepared three desserts: pumpkin pie, chocolate cheesecake, and white macadamia cookies.