AI Evaluation Methods

Reliability, evaluation, and “hallucination anxiety” are where most AI programmes quietly stall. Not because the model is weak. Because the system around it is not built to scale trust. When companies move beyond demos, three hard questions appear: →Can we rely on this output? →Do we know what “good” actually looks like? →How much human oversight is enough? The fix is not better prompting. It is a strategy and operating discipline. 𝐅𝐢𝐫𝐬𝐭: ⁣Define reliability like a product, not a vibe. Every serious AI use case should have a one-page SLO sheet with measurable targets across: →Task success ↳Right-first-time rate and rubric-based acceptance →Factual grounding ↳Evidence coverage and unsupported-claim tracking →Safety and compliance ↳Policy violations and PII leakage →Operational quality ↳Latency, cost per task, escalation to humans Now “good” is no longer opinion. It is observable. 𝐒𝐞𝐜𝐨𝐧𝐝:  evaluation must be continuous, not a one-off demo test. Use a simple loop: 𝐏lan: Define rubrics, datasets, and risk tiers 𝐃⁣o: Run offline evaluations and limited pilots 𝐂heck: Monitor drift and regressions weekly 𝐀ct: Update prompts, data, guardrails, and workflows Support this with an AI test pyramid: →Unit checks for prompts and tool behaviour →Scenario tests for real edge failures →Regression benchmarks to prevent backsliding →Live monitoring in production Add statistical control charts, and you can detect silent degradation before users do. 𝐓𝐡𝐢𝐫𝐝: reduce hallucinations by design. →Run a short failure-mode workshop and engineer controls: →Require retrieval or evidence before answering →Allow safe abstention instead of confident guessing →Add claim checking and tool validation →Use structured intake and clarifying flows You are not asking the model to behave. You are designing a system that expects failure and contains it. 𝐅𝐨𝐮𝐫𝐭𝐡: make human-in-the-loop affordable. Tier risk: →Low risk: Light sampling →Medium risk: Triggered review →High risk: Mandatory approval Escalate only when signals demand it: low confidence, missing evidence, policy flags, or novelty spikes. Review becomes targeted, fast, and a source of improvement data. 𝐅𝐢𝐧𝐚𝐥𝐥𝐲: Operate it like a capability. Track outcomes, risk, delivery speed, and cost on a single dashboard. Hold a short weekly reliability stand-up focused on regressions, failure modes, and ownership. What you end up with is simple: ↳Use case catalogue with risk tiers ↳Clear SLOs and error budgets ↳Continuous evaluation harness ↳Built-in controls ↳Targeted human review ↳Reliability cadence AI does not scale on intelligence alone. It scales on measurable trust. ♻️ Share if you found thisuseful. ➕ Follow (Jyothish Nair) for reflections on AI, change, and human-centred AI #AI #AIReliability #TrustAtScale #OperationalExcellence

This is how you measure your AI system as an AI Engineer 👇 For regular software you would track metrics like uptime, error rate, p95 latency. However, they say little about whether the system is fast where users feel it, affordable at scale or correct. Here are the metrics we track when building LLM systems. It is useful to group them by the question they answer: 𝟭. 𝗜𝘀 𝗶𝘁 𝗳𝗮𝘀𝘁? (𝗟𝗮𝘁𝗲𝗻𝗰𝘆) ➡️ Time to first token (TTFT): how long the user is exposed to a blank screen, the number that defines perceived latency. ➡️ Inter-token latency (ITL): how smoothly tokens stream after the first one. ➡️ End-to-end latency at p50 / p95 / p99, dominated by output length, track it per use case rather than globally. 𝟮. 𝗖𝗮𝗻 𝗶𝘁 𝘀𝗰𝗮𝗹𝗲? (𝗧𝗵𝗿𝗼𝘂𝗴𝗵𝗽𝘂𝘁 𝗮𝗻𝗱 𝗰𝗼𝘀𝘁) ➡️ Tokens per second per user vs total system throughput, the two trade off against each other on the same hardware. ➡️ Input and output tokens per request to measure your unit economics. ➡️ Cache hit rate - prompt caching is often the technique that reduces cost the most. ➡️ Cost per successful task, not cost per request, a cheap request that fails is a waste. 𝟯. 𝗜𝘀 𝗶𝘁 𝗰𝗼𝗿𝗿𝗲𝗰𝘁? (𝗤𝘂𝗮𝗹𝗶𝘁𝘆) ➡️ Task success rate on a labeled eval set, re-run on every prompt or model change. ➡️ Groundedness for RAG - is the answer supported by the retrieved context. ➡️ Retrieval precision@k and recall@k - generation cannot fix what retrieval never surfaced. ➡️ LLM-as-judge scores over time, calibrated against human labels. ➡️ User feedback signals: thumbs, edits to generated output, free form feedback. 𝟰. 𝗗𝗼𝗲𝘀 𝗶𝘁 𝗵𝗼𝗹𝗱 𝘂𝗽? (𝗥𝗲𝗹𝗶𝗮𝗯𝗶𝗹𝗶𝘁𝘆) ➡️ Error, timeout and rate-limit rates per provider. ➡️ Retry and fallback rate - how often you silently switch to a backup model. ➡️ Guardrail trigger and refusal rates. 𝟱. 𝗛𝗼𝘄 𝗱𝗼𝗲𝘀 𝘆𝗼𝘂𝗿 𝗮𝗴𝗲𝗻𝘁 𝗯𝗲𝗵𝗮𝘃𝗲? (𝗔𝗴𝗲𝗻𝘁 𝗺𝗲𝘁𝗿𝗶𝗰𝘀) ➡️ Tool-call error rate. ➡️ Steps and tokens per completed task - drift here means cost is rising while accuracy remains the same ➡️ Context window utilization - the early warning for compaction and truncation issues. Read more about this in my newsletter: https://lnkd.in/dhiscYbm ❗️ Latency and reliability show up on day one because standard infra emits them. Quality, cost per task, and agent behavior need deliberate instrumentation, and they are where AI systems fail in production. Which metric caught a real problem for you that the standard dashboards missed? 👇

"The LLM works great." Works great… according to what? That's the question most AI teams skip, and it's why so many models look brilliant in demos and fall apart in production. Testing an LLM isn't one thing. It's six, and using only one of them is how trust quietly breaks. Here are the 6 methods for testing LLM output quality 👇 🔹Human Evaluation - the gold standard for nuance, tone, subtle errors. Slow and costly, but irreplaceable. 🔹Automated Metrics - BLEU, ROUGE, BERTScore, perplexity. Fast and repeatable, weak on meaning. 🔹Adversarial & Red-Teaming - stress tests for jailbreaks, prompt injection, hallucinations. Critical before launch. 🔹LLM-as-a-Judge - a strong model grades outputs. Scales human-like judgment cheaply (watch for bias). 🔹Task-Specific Evaluation - custom datasets that mirror production. Measures real business value. 🔹Benchmark Testing - MMLU, HellaSwag, GSM8K, HumanEval. Comparable across models; may miss real-world tasks. The takeaway: no single method covers everything. Layer them. Save this if you build with LLMs. Which do you trust most? 👇

Explaining the Evaluation method LLM-as-a-Judge (LLMaaJ). Token-based metrics like BLEU or ROUGE are still useful for structured tasks like translation or summarization. But for open-ended answers, RAG copilots, or complex enterprise prompts, they often miss the bigger picture. That’s where LLMaaJ changes the game. 𝗪𝗵𝗮𝘁 𝗶𝘀 𝗶𝘁? You use a powerful LLM as an evaluator, not a generator. It’s given: - The original question - The generated answer - And the retrieved context or gold answer 𝗧𝗵𝗲𝗻 𝗶𝘁 𝗮𝘀𝘀𝗲𝘀𝘀𝗲𝘀: ✅ Faithfulness to the source ✅ Factual accuracy ✅ Semantic alignment—even if phrased differently 𝗪𝗵𝘆 𝘁𝗵𝗶𝘀 𝗺𝗮𝘁𝘁𝗲𝗿𝘀: LLMaaJ captures what traditional metrics can’t. It understands paraphrasing. It flags hallucinations. It mirrors human judgment, which is critical when deploying GenAI systems in the enterprise. 𝗖𝗼𝗺𝗺𝗼𝗻 𝗟𝗟𝗠𝗮𝗮𝗝-𝗯𝗮𝘀𝗲𝗱 𝗺𝗲𝘁𝗿𝗶𝗰𝘀: - Answer correctness - Answer faithfulness - Coherence, tone, and even reasoning quality 📌 If you’re building enterprise-grade copilots or RAG workflows, LLMaaJ is how you scale QA beyond manual reviews. To put LLMaaJ into practice, check out EvalAssist; a new tool from IBM Research. It offers a web-based UI to streamline LLM evaluations: - Refine your criteria iteratively using Unitxt - Generate structured evaluations - Export as Jupyter notebooks to scale effortlessly A powerful way to bring LLM-as-a-Judge into your QA stack. - Get Started guide: https://lnkd.in/g4QP3-Ue - Demo Site: https://lnkd.in/gUSrV65s - Github Repo: https://lnkd.in/gPVEQRtv - Whitepapers: https://lnkd.in/gnHi6SeW

𝔼𝕍𝔸𝕃 field note (2 of 3): Finding the benchmarks that matter for your own use cases is one of the biggest contributors to AI success. Let's dive in. AI adoption hinges on two foundational pillars: quality and trust. Like the dual nature of a superhero, quality and trust play distinct but interconnected roles in ensuring the success of AI systems. This duality underscores the importance of rigorous evaluation. Benchmarks, whether automated or human-centric, are the tools that allow us to measure and enhance quality while systematically building trust. By identifying the benchmarks that matter for your specific use case, you can ensure your AI system not only performs at its peak but also inspires confidence in its users. 🦸♂️ Quality is the superpower—think Superman—able to deliver remarkable feats like reasoning and understanding across modalities to deliver innovative capabilities. Evaluating quality involves tools like controllability frameworks to ensure predictable behavior, performance metrics to set clear expectations, and methods like automated benchmarks and human evaluations to measure capabilities. Techniques such as red-teaming further stress-test the system to identify blind spots. 👓 But trust is the alter ego—Clark Kent—the steady, dependable force that puts the superpower into the right place at the right time, and ensures these powers are used wisely and responsibly. Building trust requires measures that ensure systems are helpful (meeting user needs), harmless (avoiding unintended harm), and fair (mitigating bias). Transparency through explainability and robust verification processes further solidifies user confidence by revealing where a system excels—and where it isn’t ready yet. For AI systems, one cannot thrive without the other. A system with exceptional quality but no trust risks indifference or rejection - a collective "shrug" from your users. Conversely, all the trust in the world without quality reduces the potential to deliver real value. To ensure success, prioritize benchmarks that align with your use case, continuously measure both quality and trust, and adapt your evaluation as your system evolves. You can get started today: map use case requirements to benchmark types, identify critical metrics (accuracy, latency, bias), set minimum performance thresholds (aka: exit criteria), and choose complementary benchmarks (for better coverage of failure modes, and to avoid over-fitting to a single number). By doing so, you can build AI systems that not only perform but also earn the trust of their users—unlocking long-term value.

🚨 Public Service Announcement: If you're building LLM-based applications for internal business use, especially for high-risk functions this is for you. Define Context Clearly ------------------------ 📋 Document the purpose, expected behavior, and users of the LLM system. 🚩 Note any undesirable or unacceptable behaviors upfront. Conduct a Risk Assessment ---------------------------- 🔍 Identify potential risks tied to the LLM (e.g., misinformation, bias, toxic outputs, etc), and be as specific as possible 📊 Categorize risks by impact on stakeholders or organizational goals. Implement a Test Suite ------------------------ 🧪 Ensure evaluations include relevant test cases for the expected use. ⚖️ Use benchmarks but complement them with tests tailored to your business needs. Monitor Risk Coverage ----------------------- 📈 Verify that test inputs reflect real-world usage and potential high-risk scenarios. 🚧 Address gaps in test coverage promptly. Test for Robustness --------------------- 🛡 Evaluate performance on varied inputs, ensuring consistent and accurate outputs. 🗣 Incorporate feedback from real users and subject matter experts. Document Everything ---------------------- 📑 Track risk assessments, test methods, thresholds, and results. ✅ Justify metrics and thresholds to enable accountability and traceability. #psa #llm #testingandevaluation #responsibleAI #AIGovernance Patrick Sullivan, Khoa Lam, Bryan Ilg, Jeffery Recker, Borhane Blili-Hamelin, PhD, Dr. Benjamin Lange, Dinah Rabe, Ali Hasan

If you use LLM-as-judge, this one is worth reading. (bookmark it) It's actually one of the most effective ways to use LLM-as-a-Judge for evals. Holistic judge scores hide both their reasoning and their ceiling effects. BINEVAL decomposes each evaluation criterion into atomic yes-or-no questions, answers each independently per output, then aggregates the verdicts into calibrated multi-dimensional scores. Every question-level verdict is inspectable, so you can diagnose exactly why an output scored low, and the same verdicts feed straight back as targeted prompt-improvement signal. Across SummEval, Topical-Chat, and QAGS, it matches or beats UniEval and G-Eval, training-free, with especially strong results on factual consistency.

AI matched specialist responses on real-world consults at Stanford — but doctors couldn’t agree whether they preferred the AI or human response. 📄 New peer-reviewed study (+ David JH Wu, Fateme (Fatima) Nateghi, Vishnu Ravi, MD, Saloni Maharaj, Stephen Ma, Jonathan H. Chen et al) “Automated Evaluation of Large Language Model Response Concordance with Human Specialist Responses on eConsult Cases” 📌 The study - 40 physician-to-physician eConsults used to test how well AI replies matched board-certified specialists (cardiology, endocrinology, ID, neurology, heme/onc, etc.) - Each case included real notes + labs - GPT-4.1 generated consult replies to actual clinical queries - Real human specialists’ replies were used for comparison Doctors graded AI outputs (“concordant” vs “discordant”). ⚙️ Evaluation methods 1️⃣ LLM-as-Judge (LaJ): LLM grader compared doctor and AI replies 2️⃣ Decompose-then-Verify (DtV): LLM broke replies into atomic facts (e.g., “start metformin”) before LLM grader checked each fact for agreement. 3 internal medicine doctors reviewed all 40 cases to benchmark how reliably each automated method matched expert judgment. 📊 Key findings 1️⃣  AI’s replies were similar to actual specialist responses - GPT-4.1 answers were as consistent with human specialists as doctors were with each other - κ = 0.75, F1 = 0.89 (AI–doctor concordance) - Inter-physician κ = 0.69–0.90 (doctor–doctor concordance) 2️⃣ An AI “judge” can rate AI responses with near-human expert reliability - Best evaluator: DeepSeek R1 (F1 0.89, κ 0.75) - Gemini 2.5 Pro (F1 0.86, κ 0.70) LLM-as-Judge outperformed DtV. But DtV was more "explainable" since could compare grading against atomic facts. 3️⃣ Doctors disagreed on whether they preferred the AI or human specialist’s consult - One preferred the AI in 82% of cases (clarity, organization). - Another preferred the human in 88% of cases (nuance, tone, and contextual awareness eg. insurance considerations). 🩺 Takeaways AI can produce consults that are concordant with how a real human specialist might respond. + LLMs can evaluate AI outputs with near-human expert reliability. 📌 Limitations - Small sample: 40 eConsults and 3 physician reviewers - Conducted at single health system (Stanford) - Evaluated concordance, not clinical accuracy 📌 Why this matters Human evaluation is a big (and costly) bottleneck in clinical AI. Results show automated evaluation can reach human expert level reliability, perhaps enabling scalable validation across real-time specialty consults. 📅 Free online Stanford BMIR Colloquium “Applied Intelligence: Integrating AI Technologies Into Medical Education” 🎙️ Laurah Turner, PhD 📅 Thursday, Oct 9 | 12–1 PM PT 📍 Tapao Hall (3180 Porter Dr) + Zoom Live Stream Dr. Turner's talk will explore when to trust AI autonomously, when human oversight is essential, and when to avoid AI entirely.

"five building blocks — conceptual and technical infrastructure — needed to operationalize responsible AI ... 1. People: Empower your experts Responsible AI goals are best served by multidisciplinary teams that contain varied domain, technical, and social expertise. Rather than seeking "unicorn" hires with all dimensions of expertise, organizations should build interdisciplinary teams, ensure inclusive hiring practices, and strategically decide where RAI work is housed — i.e., whether it is centralized, distributed, or a hybrid. Embedding RAI into the organizational fabric and ensuring practitioners are sufficiently supported and influential is critical to developing stable team structures and fostering strong engagement among internal and external stakeholders. 2. Priorities: Thoughtfully triage work For responsible AI practices to be implemented effectively, teams need to clearly define the scope of this work, which can be anchored in both regulatory obligations and ethical commitments. Teams will need to prioritize across factors like risk severity, stakeholder concerns, internal capacity, and long-term impact. As technological and business pressures evolve, ensuring strategic alignment with leadership, organizational culture, and team incentives is crucial to sustaining investment in responsible practices over time. 3. Processes: Establish structures for governance Organizations need structured governance mechanisms that move beyond ad-hoc efforts to tackle emerging issues posed in the development or adoption of AI. These include standardized risk management approaches, clear internal decision-making guidance, and checks and balances to align incentives across disparate business functions. 4. Platforms: Invest in responsibility infrastructure To scale responsible practices, organizations will be well-served by investing in foundational technical and procedural infrastructure, including centralized documentation management systems, AI evaluation tools, off-the-shelf mitigation methods for common harms and failure modes, and post-deployment monitoring platforms. Shared taxonomies and consistent definitions can support cross-team alignment, while functional documentation systems make responsible AI work internally discoverable, accessible, and actionable. 5. Progress: Track efforts holistically Sustaining support for and improving responsible AI practices requires teams to diligently measure and communicate the impact of related efforts. Tailored metrics and indicators can be used to help justify resources and promote internal accountability. Organizational and topical maturity models can also guide incremental improvement and institutionalization of responsible practices; meaningful transparency initiatives can help foster stakeholder trust and democratic engagement in AI governance." Miranda Bogen, Kevin Bankston, Ruchika Joshi, Beba Cibralic, PhD, Center for Democracy & Technology, Leverhulme Centre for the Future of Intelligence

Let's say you have a dataset with 10,000 samples. You take 80% of those samples and train a model. You then evaluate that model with the remaining 20% of samples.  Let's assume the accuracy of that model is 90%. But what if you were lucky and the 2,000 samples you used to evaluate the model were easier than the rest of the dataset? If that was the case, 90% accuracy is too optimistic.  What if you were unlucky, and the 2,000 samples were more challenging than the rest of the data? In that case, 90% is too pessimistic. This is a problem. To solve it, we can use the entire dataset to evaluate the model instead of relying on a small percentage of the data. We call this process K-fold Cross-Validation, and here is how it works. 1. Partition the dataset into k smaller subsets  2. Use k-1 subsets for training  3. Use the other subset for evaluation 4. Repeat k times using a different subset each time 5. The final model performance is the average of the k-scores Look at the attached image to better understand how a 5-fold Cross-Validation process works. Some characteristics of this technique:  • It'll give you a better measure of performance • It results in less biased models  • It's more expensive to run Here is the final and critical question I have for you: Which of the models you created should you deploy in production? The answer is none of them. Here are two different strategies: The first strategy is to train a new model using the entire dataset. In a 5-Fold Cross-Validation, this will be the sixth model you train and the one you'll deploy. The downside of this strategy is having to run another complete training process. The second strategy is to deploy all five models and average their results to compute the final prediction. Here, you don't have to train another model, but you have to maintain an ensemble of models, which is more costly during inference time. I usually go with the first strategy.