AV Verification, Validation & Metrics interview cheat sheet
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Verification, validation and metrics for autonomous vehicles

A working guide to how self-driving systems are checked, trusted and measured — and, more generally, to evaluating any system whose failures are rare, expensive and safety-critical.

The document is organised as two rounds. Round 01 — V&V asks what it takes to trust a simulator: how verification differs from validation, how evidence is tiered from unit tests up to closed-course driving, and how a real programme spends its compute and triages its failures. Round 02 — Metrics asks how to design a measure that supports an actual decision, and works through the four places measurement usually goes wrong: Goodhart effects, stratification, sparse events, and uncertainty.

I first wrote this to prepare for a validation-and-verification interview, so it is shaped around the questions that come up in those conversations — mock cases at both module and architecture level, a searchable glossary, and a one-page summary for the ten minutes before you walk in. It has since turned out to work reasonably well as a standalone introduction to AV evaluation, which is why it is here.

How to use it The sidebar switches sections and the two tabs at the top switch rounds. Terms highlighted in the text jump to the glossary; Esc brings you back to where you were. English and 简体中文 carry the same content — use the toggle at top right.

自动驾驶的验证、确认与指标设计

一份关于自动驾驶系统如何被检验、被信任、被度量的工作笔记——更一般地说,也是关于如何评估任何一个「失效罕见、代价高昂、且性命攸关」的系统。

文档分为两轮。第一轮 · V&V 讨论「凭什么相信一个仿真器」:verification 与 validation 的区别、证据如何从单元测试一路分层到闭场路测、以及真实项目怎么分配算力、怎么 triage 失败。第二轮 · Metrics 讨论如何设计一个真正支撑决策的指标,并逐一走过度量最容易翻车的四个地方:Goodhart 效应、分层、稀疏事件、以及不确定度。

这份材料最初是我为一场 validation and verification 面试准备的,所以它是围绕那类对话中会出现的问题组织的——模块级和架构级的 mock case、可搜索的术语表、以及一页纸的考前速览。后来发现它本身也算一份还不错的 AV 评估入门,所以放在这里。

使用方式 左侧切换章节,顶部两个标签切换轮次。正文中高亮的术语可以跳到术语表,Esc 返回原处。中英文内容完全一致,右上角切换。

Three things worth carrying away

  1. Verification and validation answer different questions. Verification asks whether you built the system right, against a specification. Validation asks whether the specification was the right one, against reality. Confusing them is the most common failure in an evaluation programme, and no amount of test volume fixes it.
  2. A metric is only as good as the decision it supports. Before choosing a formula, name the decision, the population it is computed over, and what would make you act differently. A number without a decision attached will be optimised into meaninglessness.
  3. Rare events are a statistics problem before they are an engineering problem. When the thing you care about happens once in a million miles, most of the difficulty is in confidence intervals, stratification and exposure — not in the detector.

These generalise well beyond driving. Most of what is here applies to any agent or system evaluated on outcomes that are costly to observe — which is, more or less, what I work on.

三点值得带走的东西

  1. Verification 和 validation 回答的是两个不同的问题。Verification 问「系统是否按规格被正确地做出来了」,validation 问「这个规格本身对不对」。混淆二者是评估项目里最常见的失误,而且靠堆测试量是修不好的。
  2. 一个指标的价值上限,取决于它支撑的那个决策。选公式之前,先说清楚:这个数支撑什么决策、在什么总体上计算、什么情况下你会因此改变行动。没有决策挂钩的数字,最终一定会被优化到失去意义。
  3. 稀有事件首先是统计问题,其次才是工程问题。当你关心的事件百万英里才发生一次,大部分难度在置信区间、分层和暴露量上,而不在检测器上。

这些结论远不止适用于自动驾驶。这里的大部分内容,对任何「结果观测代价高昂」的 agent 或系统评估都成立——这大致也就是我在做的事。

Yue MaBlogResearch Last updated 2026-08-25