Journal of Technology Informatics and Engineering
Vol. 5 No. 1 (2026): APRIL | JTIE : Journal of Technology Informatics and Engineering

Bias and Hallucination Evaluation in LLMs

R Sathiyaseelan (Arunai Engineering College, Tiruvannamalai, Tamil Nadu, India)
A. B. Reshma (Arunai Engineering College, Tiruvannamalai, Tamil Nadu, India)
P. Ganga (Arunai Engineering College, Tiruvannamalai, Tamil Nadu, India)



Article Info

Publish Date
30 Apr 2026

Abstract

The largest failure modes of LLMs to-date, bias and hallucination, have measurable harms in contexts where factuality and fairness are paramount. Both areas have experienced significant research growth; however, prior work on each generally operates as a disparate body of research, and there is a gap in a methodological framework for jointly measuring, tracing, and reducing both under the same experimental conditions. We provide that framework through an empirical evaluation (not a survey) of bias propagation and hallucination generation on four illustrative domains (medical, legal, finance, human resources) through a framework that addresses the three research questions: how can bias and hallucination be measured simultaneously through a replicable, domain-specific protocol; which techniques yield statistically meaningful improvements and a consistency of effectiveness; and how do causally informed methods fare against retrieval methods when tested for factual error reduction. We report new experiments using the GPT-4, LLaMA-2, and Falcon-7B models on the MIMIC-III, CrowS-Pairs, Yahoo Finance Q3 and XNLI-HR benchmarks while keeping our prompts uniform and our random seeds fixed. Methods included structural causal modeling, retrieval-augmented generation, uncertainty-aware RLHF, and hallucination-specific fine-tuning, with experiments on each method separately before merging them into combined frameworks. We observe that RAG achieved a 45% reduction in hallucination rates and that our causally guided active learning method reduced bias disparity by 25%; together, they substantially outperform either method alone. This contributes to a repeatable method for auditing bias and hallucinations, helping ensure alignment with EU AI Act standards and similar requirements.

Copyrights © 2026






Journal Info

Abbrev

jtie

Publisher

Subject

Computer Science & IT

Description

Power Engineering Telecommunication Engineering Computer Engineering Control and Computer Systems Electronics Information technology Informatics Data and Software engineering Biomedical ...