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Confusion Matrix without Confused

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As we know, the output for classification problem is consists from two target variables, either 0 or 1; Yes or No; Positive or Negative; etc. and our model is trying to classify whether a specific data is 0 or 1; Yes or No; etc. The columns are representing the True Class, which means true or real label for the specific data. The rows are representing the Predicted Class, which means the prediction results derived from our model for the specific use case. True Positive (TP) TP is simply the count of data where the Predicted value is Positive and True value is Positive too. True Negative (TN) TN is simply the count of data where the Predicted value is Negative and True value is Negative too.


Fairness Through Counterfactual Utilities

arXiv.org Artificial Intelligence

Group fairness definitions such as Demographic Parity and Equal Opportunity make assumptions about the underlying decision-problem that restrict them to classification problems. Prior work has translated these definitions to other machine learning environments, such as unsupervised learning and reinforcement learning, by implementing their closest mathematical equivalent. As a result, there are numerous bespoke interpretations of these definitions. Instead, we provide a generalized set of group fairness definitions that unambiguously extend to all machine learning environments while still retaining their original fairness notions. We derive two fairness principles that enable such a generalized framework. First, our framework measures outcomes in terms of utilities, rather than predictions, and does so for both the decision-algorithm and the individual. Second, our framework considers counterfactual outcomes, rather than just observed outcomes, thus preventing loopholes where fairness criteria are satisfied through self-fulfilling prophecies. We provide concrete examples of how our counterfactual utility fairness framework resolves known fairness issues in classification, clustering, and reinforcement learning problems. We also show that many of the bespoke interpretations of Demographic Parity and Equal Opportunity fit nicely as special cases of our framework.


Grasp-and-Lift Detection from EEG Signal Using Convolutional Neural Network

arXiv.org Artificial Intelligence

People undergoing neuromuscular dysfunctions and amputated limbs require automatic prosthetic appliances. In developing such prostheses, the precise detection of brain motor actions is imperative for the Grasp-and-Lift (GAL) tasks. Because of the low-cost and non-invasive essence of Electroencephalography (EEG), it is widely preferred for detecting motor actions during the controls of prosthetic tools. This article has automated the hand movement activity viz GAL detection method from the 32-channel EEG signals. The proposed pipeline essentially combines preprocessing and end-to-end detection steps, eliminating the requirement of hand-crafted feature engineering. Preprocessing action consists of raw signal denoising, using either Discrete Wavelet Transform (DWT) or highpass or bandpass filtering and data standardization. The detection step consists of Convolutional Neural Network (CNN)- or Long Short Term Memory (LSTM)-based model. All the investigations utilize the publicly available WAY-EEG-GAL dataset, having six different GAL events. The best experiment reveals that the proposed framework achieves an average area under the ROC curve of 0.944, employing the DWT-based denoising filter, data standardization, and CNN-based detection model. The obtained outcome designates an excellent achievement of the introduced method in detecting GAL events from the EEG signals, turning it applicable to prosthetic appliances, brain-computer interfaces, robotic arms, etc.


Scikit Learn Confusion Matrix - Python Guides

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In this Python tutorial, we will learn How Scikit learn confusion matrix works in Python and we will also cover different examples related to Scikit learn confusion matrix. And, we will cover these topics. In this section, we will learn about how the Scikit learn confusion matrix works in python. After running the above code, we get the following output in which we can see that the confusion matrix value is printed on the screen. In this section, we will learn about how Scikit learn confusion matrix example works in python.


Uncalibrated Models Can Improve Human-AI Collaboration

arXiv.org Artificial Intelligence

In many practical applications of AI, an AI model is used as a decision aid for human users. The AI provides advice that a human (sometimes) incorporates into their decision-making process. The AI advice is often presented with some measure of "confidence" that the human can use to calibrate how much they depend on or trust the advice. In this paper, we demonstrate that presenting AI models as more confident than they actually are, even when the original AI is well-calibrated, can improve human-AI performance (measured as the accuracy and confidence of the human's final prediction after seeing the AI advice). We first learn a model for how humans incorporate AI advice using data from thousands of human interactions. This enables us to explicitly estimate how to transform the AI's prediction confidence, making the AI uncalibrated, in order to improve the final human prediction. We empirically validate our results across four different tasks -- dealing with images, text and tabular data -- involving hundreds of human participants. We further support our findings with simulation analysis. Our findings suggest the importance of and a framework for jointly optimizing the human-AI system as opposed to the standard paradigm of optimizing the AI model alone.


PEg TRAnsfer Workflow recognition challenge report: Does multi-modal data improve recognition?

arXiv.org Artificial Intelligence

This paper presents the design and results of the "PEg TRAnsfert Workflow recognition" (PETRAW) challenge whose objective was to develop surgical workflow recognition methods based on one or several modalities, among video, kinematic, and segmentation data, in order to study their added value. The PETRAW challenge provided a data set of 150 peg transfer sequences performed on a virtual simulator. This data set was composed of videos, kinematics, semantic segmentation, and workflow annotations which described the sequences at three different granularity levels: phase, step, and activity. Five tasks were proposed to the participants: three of them were related to the recognition of all granularities with one of the available modalities, while the others addressed the recognition with a combination of modalities. Average application-dependent balanced accuracy (AD-Accuracy) was used as evaluation metric to take unbalanced classes into account and because it is more clinically relevant than a frame-by-frame score. Seven teams participated in at least one task and four of them in all tasks. Best results are obtained with the use of the video and the kinematics data with an AD-Accuracy between 93% and 90% for the four teams who participated in all tasks. The improvement between video/kinematic-based methods and the uni-modality ones was significant for all of the teams. However, the difference in testing execution time between the video/kinematic-based and the kinematic-based methods has to be taken into consideration. Is it relevant to spend 20 to 200 times more computing time for less than 3% of improvement? The PETRAW data set is publicly available at www.synapse.org/PETRAW to encourage further research in surgical workflow recognition.


Inference of Multiscale Gaussian Graphical Model

arXiv.org Machine Learning

Gaussian Graphical Models (GGMs) are widely used for exploratory data analysis in various fields such as genomics, ecology, psychometry. In a high-dimensional setting, when the number of variables exceeds the number of observations by several orders of magnitude, the estimation of GGM is a difficult and unstable optimization problem. Clustering of variables or variable selection is often performed prior to GGM estimation. We propose a new method allowing to simultaneously infer a hierarchical clustering structure and the graphs describing the structure of independence at each level of the hierarchy. This method is based on solving a convex optimization problem combining a graphical lasso penalty with a fused type lasso penalty. Results on real and synthetic data are presented.


Inference and FDR Control for Simulated Ising Models in High-dimension

arXiv.org Machine Learning

The (probabilistic) graphical model consists of a collection of probability distributions that factorize according to the structure of an underlying graph [52]. The graphical model captures the complex dependencies among random variables and build large-scale multivariate statistical models, which has been used in many research areas such as hierarchical Bayesian models [27], contingency table analysis [20, 53] in categorical data analysis [1, 23, 37], constraint satisfaction [16, 15], language and speech processing [11, 31], image processing [17, 24, 28] and spatial statistics more generally [8]. In our work, we focus on the undirected graphical models, where the probability distribution factorizes according to the function defined on the cliques of the graph. The undirected graphical models have a variety of applications, including statistical physics [32], natural language processing [38], image analysis [54] and spatial statistics [43]. Specifically, we pay attention to the undirected graphical models which can be described as exponential families, a broad class of probability distributions elaborately studied in many statistical literature [4, 21, 13]. The properties of the exponential families provide some connections between the inference methods and the convex analysis [12, 29]. There are many well-known examples that are undirected graphical models viewed as exponential families, such as Ising model [32, 5], Gaussian MRF [46] and latent Dirichlet allocation [11].


Beginner's guide to machine learning in R (with step-by-step tutorial)

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If you're a graduate of economics, psychology, sociology, medicine, biostatistics, ecology, or related fields, you probably have received some training in statistics, but much less likely in machine learning. This is a problem because machine-learning algorithms are much better capable to solve many real-world applications compared with the procedures we learned in statistics class (randomized experiments, significance tests, correlation, ANOVA, linear regression, and so on). In all of these examples, statistical models are used to solve the problem, but in a different way than how you learned it in "Introduction to Statistics". In this post I want to give you a brief introduction what "machine learning" means, what the differences to "classical" statistical procedures are, and how you can train a machine learning model in R for your own use case in 8 simple steps. Think of a facial-recognition app. How does the app know whether it's John or rather Jane it's looking at? A conventional approach would be: Create an exhaustive list of features about John which can be quantitatively measured for the computer to memorize. E.g.: Look for short, brown hair, a three-day beard, a prominent nose, a scar on the left forehead, the distance between his eyes is 10.4 centimeters, he often wears a black hat, etc., that's John. The machine-learning approach works differently: You feed a computer many pictures labelled "John" or "Jane", and that's it, you don't provide any additional information – rather, you let the machine infer the important features which best discern John from Jane. It might be that the form of the cheek bones are actually a better predictor of whether or not it's John on the image, rather than the hair color or the distance between the eyes. You don't care, you let the machine figure it out. Thus, this is a data-driven (inductive) approach, where a machine *learns* the rules how to classify faces (e.g., if X1 and X2 are present, then it's likely John) from a set of training data. You don't specify these rules manually. This is why machine learning is considered (a subfield of) artificial intelligence: The machine carries out tasks without being explicitly told what to do.


Naive Bayes Classifier -- How to Successfully Use It in Python?

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The probability of randomly picking a red ball out of the bucket is 7/15. You can write it as P(red) 7/15. If we were to draw balls one at a time without replacing them, what is the probability of getting a black ball on a second attempt after drawing a red one on the first attempt? You can see that the above question is worded to provide us with the condition that needs to be satisfied first before the second attempt is made. That condition says that a red ball must be drawn during the first attempt.