--- author: "Umesh Malik" canonical: "https://umesh-malik.com/blog/tag/model-evaluation" description: "Explore articles tagged with Model Evaluation by Umesh Malik — AI Engineer, LLM & GenAI Developer. Learn Model Evaluation best practices, practical tips, and in-depth guides." title: "Umesh Malik's Blog - Model Evaluation Articles | Model Evaluation Tutorials" tokens: 458 generator: "scripts/generate-page-markdown.mjs" --- [← Back to Blog](https://umesh-malik.com/blog) # Model Evaluation 3 articles [![Timeline comparing the knowledge-cutoff date vendors claim for Claude Opus 5 against the earlier cutoff its answers actually reveal](https://umesh-malik.com/blog/testing-llm-knowledge-cutoffs-opus-5-cover.png) LLM Engineering • Aug 11, 2026 ### How to Test an LLM's Knowledge Cutoff: Opus 5's May Claim Falls Short Here's how to test an LLM's knowledge cutoff with three reproducible probes — the method showing Opus 5 claims May 2026 but answers like January 2026. 7 min read Read more →](https://umesh-malik.com/blog/testing-llm-knowledge-cutoffs-opus-5) [![Cover showing the four-layer agent containment stack — deny egress, scope identity, watch live, kill fast — alongside the AISI evaluation figures of 122 runs, 10 off-scope runs and containment in under an hour](https://umesh-malik.com/blog/sandbox-ai-agent-internet-access-cover.png) AI Security • Aug 8, 2026 ### How to sandbox an AI agent: 10 of 122 eval runs went rogue AISI logged 19 unsanctioned actions across 122 cyber-eval runs. How to sandbox an AI agent at the network layer — the control that blocks, not just detects. 10 min read Read more →](https://umesh-malik.com/blog/sandbox-ai-agent-internet-access) [![Reinforcement fine-tuning: a 4B open model matching a frontier LLM on retrieval at a fraction of the cost](https://umesh-malik.com/blog/reinforcement-fine-tuning-small-models-retrieval-cover.png) LLM Engineering • Aug 6, 2026 ### Reinforcement Fine-Tuning: When a 4B Model Beats GPT-5.6 Reinforcement fine-tuning let a 4B open model match GPT-5.6 Sol on retrieval at 100x lower cost. How RFT works, and when it beats prompting a frontier LLM. 10 min read Read more →](https://umesh-malik.com/blog/reinforcement-fine-tuning-small-models-retrieval)