Quality Prediction of RAG System Retrieval Based on Machine Learning Algorithms

The Retrieval Enhanced Generation (RAG) system improves the accuracy and reliability of content generation by retrieving external knowledge, and has been widely used in fields such as intelligent question answering and knowledge assistants. However, its core performance depends on the quality of the retrieval stage, and the relevance and factual consistency of the retrieval results directly determine the effectiveness of the generated content. However, factors such as query complexity, document noise, and domain differences in real-world scenarios can easily lead to fluctuations in retrieval quality. Traditional manual evaluation is costly and outdated, making it difficult to meet real-time optimization requirements. At the same time, existing models have limitations in complex feature fusion and parameter optimization. Therefore, this article proposes a retrieval quality prediction model that combines the Lizard Optimization Algorithm (HLOA), Convolutional Neural Network (CNN), and Bidirectional Gated Recurrent Unit (BIGRU). Correlation analysis shows that there is a strong positive correlation between retrieval rank and retrieval usefulness score, meaning that the higher the retrieval rank, the better the retrieval usefulness score; The query complexity is strongly negatively correlated with the retrieval usefulness score, meaning that the higher the query complexity, the lower the retrieval usefulness score. Integrate this model with decision trees, random forests Adaboost, The comparison of nine models, including gradient boosting tree, ExtraTrees, CatBoost, XGBoost, LightGBM, and KNN, showed that their performance was overall better: MSE (28.617), RMSE (5.349), MAE (4.401), and MAPE (17.355) were the lowest, while R (0.952) was the highest. This study provides an effective solution for accurate prediction and real-time optimization of the retrieval quality of RAG systems, helping to enhance the application value of RAG technology in practical scenarios.