Evidence Hub

A Survey of conversational AI from rule based to generative and retrieval augmented generation chatbots

V. Ghaywat, Abhyuday Singh, Aniket K. Shahade, Wasim Khan, Priyanka V. Deshmukh

Discover Artificial Intelligence, 2026

Abstract

Retrieval-Augmented Generation (RAG) has rapidly emerged as a foundational paradigm for knowledge-grounded conversational agents, particularly in high-stakes domains where factual accuracy, transparency, and adaptability are paramount. Although prior surveys have examined the evolution of chatbots or the mechanics of retrieval-augmented language models in isolation, a comprehensive, system-level synthesis of RAG-based chatbots as end-to-end conversational architectures remains limited. This survey addresses that gap by presenting a structured, design-oriented analysis of RAG-driven conversational systems through a principled framework that decomposes architectures along critical dimensions, including document segmentation and chunking strategies, embedding and indexing mechanisms, retriever and re-ranking models, knowledge integration and grounding techniques, attribution mechanisms, and evaluation methodologies. Following a transparent and reproducible literature selection protocol, we examine representative RAG implementations across both open-domain and specialized settings, systematically analyzing architectural trade-offs, interaction effects among components, recurring failure modes, and sources of performance variability that are often obscured by aggregate benchmark metrics. Beyond cataloguing techniques, the survey advances a conceptual understanding of when and why RAG systems succeed or degrade, critiques prevailing evaluation practices, and delineates emerging…

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free