arXiv Machine Learning

Unsupervised Feature Selection Using Local Intrinsic Dimensionality -- Extended Version

The paper introduces LIDFS, an unsupervised feature selection technique that uses Local Intrinsic Dimensionality (LID) to rank features based on their local discriminability. By treating each feature as a point and estimating its LID via maximum likelihood from distances to its k nearest neighboring features, LIDFS assigns higher importance to features with lower LID and refines the ranking to remove locally redundant features. Experiments on 23 high‑dimensional datasets show that LIDFS outperforms both classic and state‑of‑the‑art methods in supervised and clustering evaluations while running faster than its closest competitor.

arXiv Machine Learning
Jul 28

An Empirical Study of Feature Selection Granularity

arXiv:2607. 24145v1 Announce Type: new Abstract: Feature selection aims to identify the most informative and relevant features for a given dataset, either in terms of capturing the underlying data structure and distribution better, or with respect to the performance on a downstream task.

By Muhammad Rajabinasab, Arthur Zimek
arXiv AI
Oct 31

Worse than Random: The Importance of a Baseline for Unsupervised Feature Selection -- Extended Version

The paper argues that many newly proposed unsupervised feature selection methods are evaluated only against other methods without a proper baseline. Using random feature selection as a baseline, the authors demonstrate that several state‑of‑the‑art methods are actually outperformed in both performance and efficiency. They call for the inclusion of random selection as a baseline and for the development of better evaluation metrics to ensure realistic assessment of future methods.

By Muhammad Rajabinasab, Michael E. Houle, Oussama Chelly, Arthur Zimek
arXiv Machine Learning
Sep 11

Meta-Learning for Classifier Selection in Image Datasets: A Feature-Driven Framework for Accuracy Prediction

The paper introduces a meta‑learning framework that uses a rich set of dataset‑complexity meta‑features to predict the accuracy of different classifiers on image datasets, avoiding exhaustive training. By extracting features with autoencoders, pre‑trained networks, and dimensionality reduction, regression models estimate classifier accuracies, while clustering groups similar performers to simplify recommendations. Tested on 56 diverse image datasets, the method achieves over 86% ranking prediction accuracy, offering a scalable, interpretable solution for model selection and cost reduction.

By Zahra Nabizadeh_Shahre_Babak, Farzaneh Koohestani, Nader Karimi, Shahram Shirani, Shadrokh Samavi
arXiv AI
Oct 31

Integrated Feature Selection for classification and Representation Learning with Group-Lasso Siamese Networks

The paper introduces a novel Siamese network framework that integrates Group‑Lasso for feature selection, aiming to identify compact feature subsets that preserve intrinsic data representations while maintaining high classification performance. Two variants are proposed—one using Euclidean distance and another employing a modified Jaccard similarity for real‑valued vectors—to better handle high‑dimensional sparse data. Experiments on 12 benchmark datasets with feature dimensions up to 7,070 demonstrate that the method consistently selects discriminative features and achieves competitive or superior classification results across eight classifiers, with embedding quality evaluated via UMAP and t‑SNE.

By Nisargo Ranjan Pal, Pradeep Singh
arXiv Machine Learning
Aug 13

Towards Truly Unsupervised Evaluation of Feature Selection

arXiv:2608. 12057v1 Announce Type: new Abstract: Feature selection is one of the most important and fundamental tasks in data mining, tackled by a family of methods with an established set of evaluation techniques to measure the quality of a specific method.

By Hafiz Saud Arshad, Muhammad Rajabinasab, Arthur Zimek
arXiv AI
Oct 31

Assessing feature scorer results on high-dimensional datasets with t-SNE

The paper introduces weighted t‑SNE, a variant of t‑SNE that incorporates feature importance scores from feature scorers into the 2‑D embedding of high‑dimensional data. It explains how to implement the method, proposes using the silhouette coefficient to evaluate the resulting visualizations, and demonstrates its use on synthetic and real‑world tabular datasets with nine different feature scorers. The approach allows practitioners to compare feature scorers visually and to interpret how machine‑learning models organize data based on learned feature importance.

By Bruno Iochins Grisci, Mario Inostroza-Ponta, M\'arcio Dorn
arXiv Machine Learning
Aug 31

Curvature-Aware Radius Shrinkage for Adaptive Nearest Neighbor Classification

Curvature-Aware Radius Shrinkage for Adaptive Nearest Neighbor Classification (CARSANN) is a geometry-driven framework that adapts the spatial support of each neighborhood based on local geometric complexity. It estimates intrinsic dimensionality with TwoNN, builds an intrinsic representation via PCA, and uses a shape-operator-based estimate of local mean curvature to shrink the radius in highly curved regions while keeping a broader support in flatter areas. Experiments on over 70 OpenML datasets show that CARSANN consistently outperforms standard k‑NN and rivals other adaptive nearest‑neighbor methods, achieving a mean balanced accuracy increase from 0.6506 to 0.7528 and statistically significant improvements on most datasets.

By Alexandre L. M. Levada