Goto

Collaborating Authors

 Statistical Learning


Trying to Outrun Causality with Machine Learning: Limitations of Model Explainability Techniques for Identifying Predictive Variables

arXiv.org Machine Learning

Machine Learning explainability techniques have been proposed as a means of `explaining' or interrogating a model in order to understand why a particular decision or prediction has been made. Such an ability is especially important at a time when machine learning is being used to automate decision processes which concern sensitive factors and legal outcomes. Indeed, it is even a requirement according to EU law. Furthermore, researchers concerned with imposing overly restrictive functional form (e.g., as would be the case in a linear regression) may be motivated to use machine learning algorithms in conjunction with explainability techniques, as part of exploratory research, with the goal of identifying important variables which are associated with an outcome of interest. For example, epidemiologists might be interested in identifying `risk factors' - i.e. factors which affect recovery from disease - by using random forests and assessing variable relevance using importance measures. However, and as we demonstrate, machine learning algorithms are not as flexible as they might seem, and are instead incredibly sensitive to the underling causal structure in the data. The consequences of this are that predictors which are, in fact, critical to a causal system and highly correlated with the outcome, may nonetheless be deemed by explainability techniques to be unrelated/unimportant/unpredictive of the outcome. Rather than this being a limitation of explainability techniques per se, we show that it is rather a consequence of the mathematical implications of regression, and the interaction of these implications with the associated conditional independencies of the underlying causal structure. We provide some alternative recommendations for researchers wanting to explore the data for important variables.


Top Trending Machine Learning (ML) Algorithms To Learn In 2022

#artificialintelligence

Artificial Intelligence is rapidly becoming the present and future of technology. Machine learning algorithms have been created to handle challenging real-world situations. These algorithms are highly efficient and self-modifying, as they improve over time with the addition of more data and minimal human involvement. Let's go over the top machine learning algorithms you should be familiar with to keep up with the latest ML advancements. The algorithm depicts the relationship between two variables, one independent and the other dependent. When the independent variable is changed, it affects the dependent variable.


Starting With Linear Regression in Python – Real Python

#artificialintelligence

This is just the beginning. Data science and machine learning are driving image recognition, autonomous vehicle development, decisions in the financial and energy sectors, advances in medicine, the rise of social networks, and more. Linear regression is an important part of this. Linear regression is one of the fundamental statistical and machine learning techniques. Whether you want to do statistics, machine learning, or scientific computing, there's a good chance that you'll need it.


Cluster Analysis and Unsupervised Machine Learning in Python

#artificialintelligence

Created by Lazy Programmer Inc. English [Auto-generated], Portuguese [Auto-generated], 1 more Created by Lazy Programmer Inc. Cluster analysis is a staple of unsupervised machine learning and data science. It is very useful for data mining and big data because it automatically finds patterns in the data, without the need for labels, unlike supervised machine learning. In a real-world environment, you can imagine that a robot or an artificial intelligence won't always have access to the optimal answer, or maybe there isn't an optimal correct answer. You'd want that robot to be able to explore the world on its own, and learn things just by looking for patterns. Do you ever wonder how we get the data that we use in our supervised machine learning algorithms?


A Group Effort

Communications of the ACM

Fifty years ago, mathematician Paul Erds posed a problem to friends at one of his regular tea parties. The trio thought they would be able to come up with a solution the same afternoon. It took 49 years for other mathematicians to provide an answer. The Erds-Faber-Lovász conjecture focused on a familiar question in mathematics, one of graph coloring. However, this was not on a conventional graph, but on another more-complex structure: a hypergraph.


Journey to ML, Part 2: Skills of a (Marketable) Machine Learning Engineer

#artificialintelligence

Becoming a machine learning engineer still isn't quite as straightforward as becoming a web or mobile engineer, as we discussed in Part 1 of this series. This is despite all of the new programs geared toward machine learning both inside and outside of traditional schools. If you ask many people with the title of "Machine Learning Engineer" what they do, you'll often get wildly different answers. The goal of this post is to help you put together the beginnings of a mental semantic tree (Khan Academy's example of such a tree) for learning machine learning (à la Elon Musk's now famous method). As such, this post is probably going to have a bit more lists and hyperlinks than previous (or future) posts in this series. So, based on my own experiences, as well as reaching out to hundreds of machine learning engineers in both academia and industry, here's an overview of the soft skills, basic technical skills, and more specialized skills you'll need.


Top 6 Machine Learning Algorithms for Classification

#artificialintelligence

The easiest way to distinguish a supervised learning and unsupervised learning is to see whether the data is labelled or not. Supervised learning learns a function to make prediction of a defined label based on the input data. It can be either classifying data into a category (classification problem) or forecasting an outcome (regression algorithms). Reinforcement learning is another type of machine learning, where the agents learn to take actions based on its interaction with the environment, with the aim to maximize rewards. It is most similar to the learning process of human, following a trial-and-error approach.


Logistic Regression Algorithm in Java

#artificialintelligence

Regression analysis is a technique used to determine the relationship between the dependent and the independent variable (s) for prediction purposes. It is a good tool for data modelling and analysis. There are different regression techniques. Our focus will be on Logistic Regression. Logistic Regression is suitable when there are more than one independent variables in a dataset.


Policy Learning for Optimal Individualized Dose Intervals

arXiv.org Machine Learning

We study the problem of learning individualized dose intervals using observational data. There are very few previous works for policy learning with continuous treatment, and all of them focused on recommending an optimal dose rather than an optimal dose interval. In this paper, we propose a new method to estimate such an optimal dose interval, named probability dose interval (PDI). The potential outcomes for doses in the PDI are guaranteed better than a pre-specified threshold with a given probability (e.g., 50%). The associated nonconvex optimization problem can be efficiently solved by the Difference-of-Convex functions (DC) algorithm. We prove that our estimated policy is consistent, and its risk converges to that of the best-in-class policy at a root-n rate. Numerical simulations show the advantage of the proposed method over outcome modeling based benchmarks. We further demonstrate the performance of our method in determining individualized Hemoglobin A1c (HbA1c) control intervals for elderly patients with diabetes.


"Is not the truth the truth?": Analyzing the Impact of User Validations for Bus In/Out Detection in Smartphone-based Surveys

arXiv.org Artificial Intelligence

Passenger flow allows the study of users' behavior through the public network and assists in designing new facilities and services. This flow is observed through interactions between passengers and infrastructure. For this task, Bluetooth technology and smartphones represent the ideal solution. The latter component allows users' identification, authentication, and billing, while the former allows short-range implicit interactions, device-to-device. To assess the potential of such a use case, we need to verify how robust Bluetooth signal and related machine learning (ML) classifiers are against the noise of realistic contexts. Therefore, we model binary passenger states with respect to a public vehicle, where one can either be-in or be-out (BIBO). The BIBO label identifies a fundamental building block of continuously-valued passenger flow. This paper describes the Human-Computer interaction experimental setting in a semi-controlled environment, which involves: two autonomous vehicles operating on two routes, serving three bus stops and eighteen users, as well as a proprietary smartphone-Bluetooth sensing platform. The resulting dataset includes multiple sensors' measurements of the same event and two ground-truth levels, the first being validation by participants, the second by three video-cameras surveilling buses and track. We performed a Monte-Carlo simulation of labels-flip to emulate human errors in the labeling process, as is known to happen in smartphone surveys; next we used such flipped labels for supervised training of ML classifiers. The impact of errors on model performance bias can be large. Results show ML tolerance to label flips caused by human or machine errors up to 30%.