---
_id: '6898'
abstract:
- lang: eng
  text: 'The labeling process for supervised learning is costly and time-consuming,
    and is often impractical to scale due to real-world constraints. Active learning
    (AL) addresses this challenge by strategically selecting representative and informative
    data points to reduce labeling efforts. This paper focuses on an AL scenario in
    which only a very limited number of labels can be acquired. We propose an algorithm
    operating in two phases: (1) an exploration phase that prioritizes representative
    and diverse data points using density-driven criteria, and (2) an exploitation
    phase that combines predictive uncertainty with density weighting to select informative
    samples from densely populated regions. This enhances both representativeness
    and informativeness. Our results demonstrate significant improvements in model
    quality compared to other algorithms typically employed for this scenario, across
    various scenarios involving imbalanced data in classification tasks and skewness
    in regression tasks. Through this work, we aim to provide a new algorithm for
    this scenario and investigate general principles for AL. While most AL studies
    focus on either classification or regression, our work applies the algorithms
    to both. Therefore, we can analyze the differences between classification and
    regression problems and their effects on AL strategies. Furthermore, we explore
    different categories of AL criteria and their effectiveness in the low-budget
    regime. These results also provide insight into the cold-start problem, which
    involves selecting an initial labeled set and is faced by many model-based AL
    methods.'
alternative_id:
- '6899'
author:
- first_name: Bjarne
  full_name: Jaster, Bjarne
  id: '252434'
  last_name: Jaster
  orcid: 0000-0002-8362-5369
- first_name: Alaa
  full_name: Tharwat, Alaa
  id: '238549'
  last_name: Tharwat
- first_name: Eiram Mahera
  full_name: Sheikh, Eiram Mahera
  last_name: Sheikh
- first_name: Martin
  full_name: Kohlhase, Martin
  id: '226669'
  last_name: Kohlhase
  orcid: 0009-0002-9374-0720
- first_name: Wolfram
  full_name: Schenck, Wolfram
  id: '224375'
  last_name: Schenck
  orcid: 0000-0003-3300-2048
citation:
  alphadin: '<span style="font-variant:small-caps;">Jaster, Bjarne</span> ; <span
    style="font-variant:small-caps;">Tharwat, Alaa</span> ; <span style="font-variant:small-caps;">Sheikh,
    Eiram Mahera</span> ; <span style="font-variant:small-caps;">Kohlhase, Martin</span>
    ; <span style="font-variant:small-caps;">Schenck, Wolfram</span>: Low Query Budget
    Active Learning for Classification and Regression. In: <span style="font-variant:small-caps;">Koprinska,
    I.</span> ; <span style="font-variant:small-caps;">Mendes-Moreira, J.</span> ;
    <span style="font-variant:small-caps;">Branco, P.</span> (Hrsg.): <i>Machine Learning
    and Principles and Practice of Knowledge Discovery in Databases. International
    Workshops of ECML PKDD 2025, Porto, Portugal, September 15–19, 2025, Revised Selected
    Papers, Part IV</i>, <i>Communications in Computer and Information Science</i>.
    Cham : Springer Nature Switzerland, 2026, S. 5–21'
  ama: 'Jaster B, Tharwat A, Sheikh EM, Kohlhase M, Schenck W. Low Query Budget Active
    Learning for Classification and Regression. In: Koprinska I, Mendes-Moreira J,
    Branco P, eds. <i>Machine Learning and Principles and Practice of Knowledge Discovery
    in Databases. International Workshops of ECML PKDD 2025, Porto, Portugal, September
    15–19, 2025, Revised Selected Papers, Part IV</i>. Communications in Computer
    and Information Science. Cham: Springer Nature Switzerland; 2026:5-21. doi:<a
    href="https://doi.org/10.1007/978-3-032-19105-2_1">10.1007/978-3-032-19105-2_1</a>'
  apa: 'Jaster, B., Tharwat, A., Sheikh, E. M., Kohlhase, M., &#38; Schenck, W. (2026).
    Low Query Budget Active Learning for Classification and Regression. In I. Koprinska,
    J. Mendes-Moreira, &#38; P. Branco (Eds.), <i>Machine Learning and Principles
    and Practice of Knowledge Discovery in Databases. International Workshops of ECML
    PKDD 2025, Porto, Portugal, September 15–19, 2025, Revised Selected Papers, Part
    IV</i> (pp. 5–21). Cham: Springer Nature Switzerland. <a href="https://doi.org/10.1007/978-3-032-19105-2_1">https://doi.org/10.1007/978-3-032-19105-2_1</a>'
  bibtex: '@inproceedings{Jaster_Tharwat_Sheikh_Kohlhase_Schenck_2026, place={Cham},
    series={Communications in Computer and Information Science}, title={Low Query
    Budget Active Learning for Classification and Regression}, DOI={<a href="https://doi.org/10.1007/978-3-032-19105-2_1">10.1007/978-3-032-19105-2_1</a>},
    booktitle={Machine Learning and Principles and Practice of Knowledge Discovery
    in Databases. International Workshops of ECML PKDD 2025, Porto, Portugal, September
    15–19, 2025, Revised Selected Papers, Part IV}, publisher={Springer Nature Switzerland},
    author={Jaster, Bjarne and Tharwat, Alaa and Sheikh, Eiram Mahera and Kohlhase,
    Martin and Schenck, Wolfram}, editor={Koprinska, Irena and Mendes-Moreira, João
    and Branco, PaulaEditors}, year={2026}, pages={5–21}, collection={Communications
    in Computer and Information Science} }'
  chicago: 'Jaster, Bjarne, Alaa Tharwat, Eiram Mahera Sheikh, Martin Kohlhase, and
    Wolfram Schenck. “Low Query Budget Active Learning for Classification and Regression.”
    In <i>Machine Learning and Principles and Practice of Knowledge Discovery in Databases.
    International Workshops of ECML PKDD 2025, Porto, Portugal, September 15–19, 2025,
    Revised Selected Papers, Part IV</i>, edited by Irena Koprinska, João Mendes-Moreira,
    and Paula Branco, 5–21. Communications in Computer and Information Science. Cham:
    Springer Nature Switzerland, 2026. <a href="https://doi.org/10.1007/978-3-032-19105-2_1">https://doi.org/10.1007/978-3-032-19105-2_1</a>.'
  ieee: B. Jaster, A. Tharwat, E. M. Sheikh, M. Kohlhase, and W. Schenck, “Low Query
    Budget Active Learning for Classification and Regression,” in <i>Machine Learning
    and Principles and Practice of Knowledge Discovery in Databases. International
    Workshops of ECML PKDD 2025, Porto, Portugal, September 15–19, 2025, Revised Selected
    Papers, Part IV</i>, Porto, Portugal, 2026, pp. 5–21.
  mla: Jaster, Bjarne, et al. “Low Query Budget Active Learning for Classification
    and Regression.” <i>Machine Learning and Principles and Practice of Knowledge
    Discovery in Databases. International Workshops of ECML PKDD 2025, Porto, Portugal,
    September 15–19, 2025, Revised Selected Papers, Part IV</i>, edited by Irena Koprinska
    et al., Springer Nature Switzerland, 2026, pp. 5–21, doi:<a href="https://doi.org/10.1007/978-3-032-19105-2_1">10.1007/978-3-032-19105-2_1</a>.
  short: 'B. Jaster, A. Tharwat, E.M. Sheikh, M. Kohlhase, W. Schenck, in: I. Koprinska,
    J. Mendes-Moreira, P. Branco (Eds.), Machine Learning and Principles and Practice
    of Knowledge Discovery in Databases. International Workshops of ECML PKDD 2025,
    Porto, Portugal, September 15–19, 2025, Revised Selected Papers, Part IV, Springer
    Nature Switzerland, Cham, 2026, pp. 5–21.'
conference:
  end_date: 2025-09-19
  location: Porto, Portugal
  name: ECML PKDD 2025
  start_date: 2025-09-15
date_created: 2026-05-10T07:55:29Z
date_updated: 2026-05-11T08:24:11Z
doi: 10.1007/978-3-032-19105-2_1
editor:
- first_name: Irena
  full_name: Koprinska, Irena
  last_name: Koprinska
- first_name: João
  full_name: Mendes-Moreira, João
  last_name: Mendes-Moreira
- first_name: Paula
  full_name: Branco, Paula
  last_name: Branco
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://rdcu.be/fh03T
oa: '1'
page: 5-21
place: Cham
project:
- _id: f432a2ee-bceb-11ed-a251-a83585c5074d
  name: Institute for Data Science Solutions
publication: Machine Learning and Principles and Practice of Knowledge Discovery in
  Databases. International Workshops of ECML PKDD 2025, Porto, Portugal, September
  15–19, 2025, Revised Selected Papers, Part IV
publication_identifier:
  eisbn:
  - 978-3-032-19105-2
  eissn:
  - 1865-0937
  isbn:
  - 978-3-032-19104-5
  issn:
  - 1865-0929
publication_status: published
publisher: Springer Nature Switzerland
series_title: Communications in Computer and Information Science
status: public
title: Low Query Budget Active Learning for Classification and Regression
type: conference
user_id: '220548'
year: '2026'
...
