Jurnal Ilmiah Multidisiplin Indonesia
Vol. 5 No. 07 (2026): Jurnal Ilmiah Multidisplin Indonesia (JIM-ID), 2026

Implementation of FastText- and Hybrid Search-Based Retrieval-Augmented Generation for PDF Document Processing: A Case Study of a Booking Engine Chatbot System

Dewa Gede Indra Putra (Universitas Primakara, Bali)
Eddy Muntina Dharma (Universitas Primakara, Bali)
Ida Bagus Kresna Sudiatmika (Universitas Primakara, Bali)



Article Info

Publish Date
22 Jul 2026

Abstract

This study proposes and evaluates a Retrieval-Augmented Generation (RAG) system integrating ChatGPT with FastText word embeddings for processing Indonesian-language PDF documents. The limitations of Large Language Models (LLMs) in handling domain-specific queries motivated the development of an RAG architecture with an advanced retrieval strategy. The CRISP-DM methodology was applied to compare two models: (1) a Baseline Model using pure FastText cosine similarity search, and (2) a Proposed Model combining Hybrid Search (FastText + BM25 with dynamic weighting), Maximal Marginal Relevance (MMR), and Cross-Encoder TF-IDF re-ranking. Evaluation was conducted using the RAGAS framework with five metrics—Context Relevance, Context Precision, Context Recall, Faithfulness, and Answer Relevance—across 20 test queries on the PT Omni Hottilier Booking Engine user guide. Results show that the Proposed Model outperformed the Baseline on 16 of 20 queries (80%), with the Overall Score increasing from 0.7853 to 0.8572 (+9.16%). The most significant improvements were observed in Context Relevance (+19.85%), Context Recall (+16.76%), and Faithfulness (+14.76%). The developed architecture is proven effective as an adaptive solution for transforming technical documents into intelligent chatbot knowledge bases, particularly for the morphologically complex Indonesian language.

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Journal Info

Abbrev

esaprom

Publisher

Subject

Agriculture, Biological Sciences & Forestry Computer Science & IT Earth & Planetary Sciences Engineering Physics

Description

Jurnal Ilmiah Multidisiplin Indonesia (JIM-ID) is a peer-reviewed journal regularly published by the SEAN Institute every three months. namely, several research publications to publish multi-disciplinary articles with general topics on engineering, science, agriculture, plantations, forestry and ...