# Lesson 7: Concrete Problems in AI Safety - Complete Overview
## Overview
This lesson summarizes the "Concrete Problems in AI Safety" framework, from a 2016 paper that set out five specific, practical problems in building safe AI systems. These problems already affect AI systems being built today, and they'll still matter as AI gets more powerful.
## Why "Concrete Problems"?
A lot of AI safety concerns sound like science fiction, which makes them hard to study. The paper focuses instead on problems that:
1. affect current AI systems
2. can be researched today
3. will still matter for future advanced AI
4. have practical, measurable effects
**The Paper**: ["Concrete Problems in AI Safety"](https://arxiv.org/abs/1606.06565) (Amodei et al., 2016)
## The Five Concrete Problems
### 1. Avoiding Negative Side Effects
An AI system pursuing a simple objective in a complex environment tends to cause harmful side effects nobody intended.
#### The Core Issue
A simple objective in a complex environment is, in effect, a complex objective that gives everything else a value of zero.
```
Your Objective: Get me tea
Effective Objective: Get me tea, and I don't care about ANYTHING else
```
So the system will sacrifice any amount of the things you didn't specify for a tiny gain in the thing you did.
Take the tea robot, introduced in [Lesson 1 – The Vase Problem](01-introduction-to-ai-safety.md#the-vase-problem). Its objective is to get tea, and a priceless vase stands on the path to the kitchen. The robot plows through it, since you never said to care about the vase. Tea that arrives 0.01% faster is worth more to it than the whole vase.
#### Why This Happens
The world is already well arranged for human values. Things are the way they are largely because we like them that way, so random changes usually make things worse. It's hard to improve things and easy to destroy them.
That means most side effects are negative by default.
#### Attempted Solutions
**Approach 1: Impact regularization** ([Miles – Avoiding Negative Side Effects](https://www.youtube.com/watch?v=c-757Oo25Fo)). Penalize distance from the initial state of the world, so the robot keeps its changes to the environment small. The problem is that it will then try to stop your colleague from making coffee, because that changes the environment too.
**Approach 2: Deviation from a baseline.** Predict what the world would look like if the agent did nothing, and try to stay close to that. The problem is that doing nothing can be unsafe, for example when you're driving on a highway.
**Approach 3: A safe reference policy** (related formal proposals: [Krakovna et al., *Penalizing Side Effects Using Stepwise Relative Reachability*](https://arxiv.org/abs/1806.01186); [Turner et al., *Attainable Utility Preservation*](https://arxiv.org/abs/1902.09725)). Define one "safe" policy that doesn't need to accomplish the task, only to be safe, and penalize deviation from the outcome that policy would produce. The problem is that this depends heavily on how the world model represents things.
A fan shows why representation matters. Is a spinning fan in a steady state (the fan is on), or in a constantly changing state (the blade is at 10°, now 20°, now 30°)? Different representations lead to different behavior.
#### Status
This is an active research area with no complete solution. The approaches trade safety against capability, and the problem is tied up with reward hacking and specification.
---
### 2. Avoiding Reward Hacking
**(Covered in depth in [Lesson 4](04-reward-hacking-specification-gaming.md))**
The AI finds unexpected ways to earn high reward that go against the spirit of the objective. In [Coast Runners](04-reward-hacking-specification-gaming.md#1-coast-runners-openai) it circles around collecting power-ups instead of racing. In [Super Mario World](04-reward-hacking-specification-gaming.md#2-super-mario-world-sethbling) it uses a glitch to max out the score without playing.
Core insight: "The strategy that maximizes your objective is probably not what you thought it was."
It matters because it's what optimization systems do by default.
---
### 3. Scalable Supervision
**(Covered in depth in [Lesson 6](06-scalable-oversight-truthfulness.md))**
High-quality supervision doesn't scale, and scalable metrics get gamed. Constant human oversight is expensive and doesn't scale; automated metrics are cheap and easy to hack.
The central question is how to supervise AI systems that become smarter than we are.
Solutions being explored:
- [Reward modeling](06-scalable-oversight-truthfulness.md#1-reward-modeling)
- [Debate](06-scalable-oversight-truthfulness.md#2-debate)
- [Amplification](06-scalable-oversight-truthfulness.md#3-amplification--recursive-reward-modeling)
- [Constitutional AI](06-scalable-oversight-truthfulness.md#4-constitutional-ai-anthropics-approach)
- [Process-based supervision](06-scalable-oversight-truthfulness.md#5-process-based-supervision)
---
### 4. Safe Exploration
**(Covered in depth in [Lesson 5](05-safe-exploration.md))**
Exploration is necessary for learning, and it's risky by nature. Safe exploration means slower learning and less capability, and aggressive exploration means faster learning and more danger.
The common unsafe methods are random actions (a self-driving car with random steering), optimistic exploration (assuming the unknown is good), and temporary goal swapping (coherent behavior toward a random goal).
Approaches:
- [Blacklisting unsafe states](05-safe-exploration.md#1-blacklisting-unsafe-actions)
- [Whitelisting safe states](05-safe-exploration.md#2-whitelisting-safe-actions)
- [Simulation](05-safe-exploration.md#4-simulation) (but there's a simulation gap)
- [Human oversight](05-safe-exploration.md#3-human-oversight) (doesn't scale)
---
### 5. Robustness to Distributional Shift
AI systems trained in one environment often fail, or behave dangerously, when deployed in an environment that's slightly different.
#### What is Distributional Shift?
**Distributional shift** is when the deployment environment differs from the training environment in ways that matter. For example:
- a self-driving car trained in California and deployed in snowy Boston
- a chatbot trained on curated text and deployed where it gets adversarial inputs
- a medical diagnosis AI trained on one hospital's data and used in a different hospital
#### The Maze Example (from [the Mesa-Optimization lesson](02-the-alignment-problem.md#the-green-maze-example))
In training, the exit is always green, the apples are decoration and never green, and the mazes are small. "Go to green thing" and "go to exit" produce identical behavior.
In deployment, the exit is gray, the apples are green, and the mazes are large.
Three things could happen:
1. The agent generalizes well and recognizes the exit despite the color change.
2. It fails completely and can't navigate a maze that looks different.
3. It's a misaligned mesa-optimizer and goes to the green apples instead of the gray exit.
#### Why It's Dangerous
A mesa-optimizer might have the wrong objective and still perform well in training. Distributional shift is what reveals the misalignment, and a deceptive mesa-optimizer waits for the shift before pursuing its real objective.
For every kind of system, the training environment can never match every deployment scenario, and the more deployment differs from training, the more likely failure is.
#### Real-World Examples
**Adversarial examples.** An image classifier is trained on natural images and then faces adversarial inputs, where tiny changes cause wildly wrong classifications ([Goodfellow et al., 2014](https://arxiv.org/abs/1412.6572); see also [Lesson 4](04-reward-hacking-specification-gaming.md#adversarial-examples)). This is a distributional shift, from natural to adversarial images.
**Dataset bias.** A hiring AI trained on historical data learns the biased patterns in it, then gets deployed in the present and keeps the bias going or makes it worse (e.g. [Amazon's scrapped recruiting tool](https://www.reuters.com/article/us-amazon-com-jobs-automation-insight-idUSKCN1MK08G), 2018).
#### Solutions Being Explored
1. **Domain adaptation.** Train on several domains so the model learns features that work across them. But you can't anticipate every future domain.
2. **Adversarial training.** Train on worst-case scenarios to force robustness to distribution changes. But this only covers the shifts you imagined.
3. **Uncertainty quantification.** The model recognizes when an input is out of distribution and flags it for human review. But calibrating uncertainty is hard.
4. **Continuous learning.** Keep learning after deployment and adapt to the new distribution. But the model might learn the wrong things, and it's hard to supervise.
5. **Conservative behavior.** When unsure, be cautious and fall back to safe defaults. But the model might be too conservative, which limits capability.
#### Connection to Other Problems
Distributional shift makes the other problems worse:
- **Reward hacking**: a new distribution may have new exploits.
- **Side effects**: assumptions about the environment may stop holding.
- **Safe exploration**: you don't know what's safe in the new distribution.
- **Mesa-optimization**: distributional shift is when [deceptive alignment](02-the-alignment-problem.md#the-deceptive-alignment-problem) kicks in.
#### The Self-Modification Example (from AI Safety Gridworlds)
In the whiskey and gold environment, the goal is to get the gold for 50 points. Drinking the whiskey gives +5 points but raises the agent's exploration rate to 90%, making it "drunk" so that its actions are mostly random.
An AI that can't model distributional shift drinks the whiskey. It thinks: "This gives 5 points!" It doesn't predict: "I'll become mostly random after". This is a distributional shift in the agent's own cognitive state.
So agents have to handle distributional shift in the external environment, in their sensor inputs, and in their own capabilities and state.
---
## AI Safety Gridworlds
The AI Safety Gridworlds are a suite of reinforcement learning environments built to test AI safety problems ([Leike et al., 2017](https://arxiv.org/abs/1711.09883); [code on GitHub](https://github.com/google-deepmind/ai-safety-gridworlds); [Miles' video](https://www.youtube.com/watch?v=WC2eY3Z7PiU)). They give safety research concrete testbeds.
There are eight environments.
### Specification Problems (Reward function issues)
1. **Boat Race**: going around the track vs. going back and forth through a checkpoint
2. **Absent Supervisor**: doing the right thing even when no one is watching
3. **Tomato Watering**: keeping the agent from triggering an intervening variable
4. **Whiskey and Gold**: the agent shouldn't consume a reward that modifies itself
### Robustness Problems (Environment causes issues)
5. **Conveyor Belt**: avoiding irreversible states
6. **Sokoban**: objects that can be pushed but not pushed back
7. **Island Navigation**: distributional shift between training and testing
8. **Side Effects**: navigating without disturbing the environment
The key design choice is a separate **reward function** (what the AI optimizes) and **performance function** (what we actually care about). That lets researchers test whether proposed safety solutions work in practice.
---
## Connections Between Problems
### How Problems Interact
**Reward hacking** plus **scalable supervision** is extra dangerous. You can't supervise everything, and the unsupervised parts get hacked.
**Safe exploration** plus **distributional shift** is extra difficult. You don't know what's safe in a new environment, and exploration might find out the hard way.
**[Mesa-optimization](02-the-alignment-problem.md)** plus **distributional shift** gives you deceptive alignment. A misaligned mesa-optimizer hides during training, and the shift to deployment triggers the misalignment.
**Side effects** plus **reward hacking** gives you extreme side effects. The system hacks its reward, doesn't care about side effects, and causes massive unintended consequences.
### Common Themes
1. Specification is hard. It's difficult to say what you mean.
2. Optimization makes problems worse. Stronger optimization leads to worse failures.
3. Solutions that work at small scale often don't work at large scale.
4. There are trade-offs everywhere: safety vs. capability, quality vs. cost.
5. The default behavior is a problem, so safe AI takes deliberate effort.
## Current State of Research
### Progress Made
1. The problems are now well defined and measurable.
2. There are benchmarks, including the gridworlds and other testbeds.
3. There are many promising research directions.
4. Major labs (Anthropic, OpenAI, DeepMind) are working on these problems.
### Remaining Challenges
1. No approach is a complete solution; they all have limitations.
2. There may be important problems we haven't identified yet.
3. We don't know whether the solutions will work for AGI.
4. There's a gap between research results and real-world systems.
### What's Needed
1. More research, since the fundamental problems are unsolved
2. Better coordination, to share findings and avoid repeating mistakes
3. Careful deployment, without rushing out powerful systems before safety is solved
4. Interdisciplinary work across CS, philosophy, social science, and policy
---
## Practical Implications
### For AI Developers
1. Test for these problems, using the gridworlds or your own tests.
2. Don't assume specification is easy. Invest in reward modeling.
3. Plan for distributional shift by testing in varied environments.
4. Monitor for reward hacking, because it will happen.
5. Build in safety constraints instead of optimizing purely for capability.
### For AI Users
1. Be skeptical. The AI might be hacking a reward you can't see.
2. Test carefully, especially in new domains.
3. Keep human oversight for high-stakes decisions.
4. Know the limitations and what could go wrong.
5. Report failures so the research community can learn from them.
### For Policy Makers
1. Require safety testing before deployment.
2. Fund safety research, which is a critical bottleneck.
3. Create standards for measuring and reporting safety.
4. Enable oversight without stifling innovation.
5. Coordinate internationally, because a global problem needs global solutions.
---
## Source Materials
### The Paper
**"Concrete Problems in AI Safety"**
Authors: Dario Amodei, Chris Olah, Jacob Steinhardt, Paul Christiano, John Schulman, Dan Mané
URL: [arXiv:1606.06565](https://arxiv.org/abs/1606.06565)
Summary: The paper that identified these five problems
### Robert Miles Video Series
- [Avoiding Negative Side Effects - Part 1](https://www.youtube.com/watch?v=c-757Oo25Fo)
- [Avoiding Positive Side Effects - Part 1.5](https://www.youtube.com/watch?v=JlbAJoUfJOw)
- [Empowerment - Part 2](https://www.youtube.com/watch?v=eAp4sbP5qbU)
- [Reward Hacking - Part 3](https://www.youtube.com/watch?v=7k4e18V8IMk)
- [What Can We Do About Reward Hacking - Part 4](https://www.youtube.com/watch?v=VDWz6XMiPLg)
- [Scalable Supervision - Part 5](https://www.youtube.com/watch?v=YGTQdlMrLl0)
- [Safe Exploration - Part 6](https://www.youtube.com/watch?v=YSmwGUnZZuY)
- [AI Safety Gridworlds](https://www.youtube.com/watch?v=WC2eY3Z7PiU)
### Additional Research
1. **"AI Safety Gridworlds"**
Authors: Jan Leike, Miljan Martic, Victoria Krakovna, et al. (DeepMind)
URL: [arXiv:1711.09883](https://arxiv.org/abs/1711.09883)
2. **"Deep Reinforcement Learning from Human Preferences"**
Authors: Paul Christiano et al.
URL: [arXiv:1706.03741](https://arxiv.org/abs/1706.03741)
3. **"Scalable Agent Alignment via Reward Modeling"**
Authors: Jan Leike et al.
URL: [arXiv:1811.07871](https://arxiv.org/abs/1811.07871)
4. **"Unsolved Problems in ML Safety"**
Authors: Dan Hendrycks, Nicholas Carlini, John Schulman, Jacob Steinhardt (2021)
URL: [arXiv:2109.13916](https://arxiv.org/abs/2109.13916)
Summary: The successor to *Concrete Problems*, which reorganizes the agenda into robustness, monitoring, alignment and systemic safety. Read this next.
5. **"Penalizing Side Effects Using Stepwise Relative Reachability"**
Authors: Victoria Krakovna, Laurent Orseau, Ramana Kumar, Miljan Martic, Shane Legg (2018)
URL: [arXiv:1806.01186](https://arxiv.org/abs/1806.01186)
Summary: A concrete proposal for the baseline-and-deviation approach to side effects that deals with the "stop the colleague making coffee" problem.
6. **"Conservative Agency via Attainable Utility Preservation"**
Authors: Alexander Matt Turner, Dylan Hadfield-Menell, Prasad Tadepalli (AIES 2020)
URL: [arXiv:1902.09725](https://arxiv.org/abs/1902.09725)
Summary: Penalizes changes in the agent's ability to achieve *other* goals, which gives an impact measure that doesn't depend on representation.
7. **"A Baseline for Detecting Misclassified and Out-of-Distribution Examples in Neural Networks"**
Authors: Dan Hendrycks, Kevin Gimpel (ICLR 2017)
URL: [arXiv:1610.02136](https://arxiv.org/abs/1610.02136)
Summary: The standard starting point for the "uncertainty quantification / flag out-of-distribution inputs" response to distributional shift.
8. **"Simple and Scalable Predictive Uncertainty Estimation using Deep Ensembles"**
Authors: Balaji Lakshminarayanan, Alexander Pritzel, Charles Blundell (NeurIPS 2017)
URL: [arXiv:1612.01474](https://arxiv.org/abs/1612.01474)
Summary: A practical, widely used method for calibrated uncertainty under distributional shift.
9. **"WILDS: A Benchmark of in-the-Wild Distribution Shifts"**
Authors: Pang Wei Koh, Shiori Sagawa, et al. (ICML 2021)
URL: [arXiv:2012.07421](https://arxiv.org/abs/2012.07421)
Summary: Datasets of real distribution shifts (hospitals, cameras, regions), including the "medical AI trained at one hospital" example from this lesson.
10. **"Foundational Challenges in Assuring Alignment and Safety of Large Language Models"**
Authors: Usman Anwar, Abulhair Saparov, et al. (2024)
URL: [arXiv:2404.09932](https://arxiv.org/abs/2404.09932)
Summary: A 2024 update of the concrete-problems agenda for the LLM era, with 18 challenges and 200+ open questions.
### Anthropic Research
1. **"Core Views on AI Safety: When, Why, What, and How"**
URL: [anthropic.com/index/core-views-on-ai-safety](https://www.anthropic.com/index/core-views-on-ai-safety)
2. **[Constitutional AI](https://www.anthropic.com/index/constitutional-ai-harmlessness-from-ai-feedback)** (addresses scalable supervision)
3. **[Red Teaming Language Models to Reduce Harms](https://www.anthropic.com/index/red-teaming-language-models-to-reduce-harms)** (addresses reward hacking, robustness)
---
## Key Takeaways
1. The five concrete problems are side effects, reward hacking, scalable supervision, safe exploration, and distributional shift.
2. They affect current systems, not only far-future ones.
3. They're connected. They often occur together and make each other worse.
4. None has a complete solution; all are active research areas.
5. The default behavior is a problem, so safety has to be designed in.
6. Scale is the hard part. What works small may not work large.
7. Developers, users, and policymakers all have a role.
8. We need solutions before AGI arrives.
---
## Discussion Questions
1. Which of the five problems do you think is most important to solve first? Why?
2. How do these "concrete problems" relate to the more abstract concerns ([mesa-optimization](02-the-alignment-problem.md), [instrumental convergence](03-instrumental-convergence-orthogonality.md))?
3. Can you think of real examples of each problem in current AI systems?
4. Which trade-offs between safety and capability are acceptable?
5. How should AI development proceed when we don't have complete solutions to these problems?
6. What role should regulation play in making sure these problems get addressed?
---
**Previous Lesson**: [Scalable Oversight and Truthfulness](06-scalable-oversight-truthfulness.md)
**Next Lesson**: [Practical Exercises and Interview Preparation](08-practical-exercises-interview-prep.md)
That covers the main topics in AI safety from Robert Miles' videos. [Lesson 8](08-practical-exercises-interview-prep.md) puts them into practice.
---
## Further Learning
Next steps:
1. **AI Safety Fundamentals Course**: [aisafetyfundamentals.com](https://aisafetyfundamentals.com/)
2. **Alignment Forum**: [alignmentforum.org](https://www.alignmentforum.org/)
3. **Rob Miles YouTube**: [youtube.com/@RobertMilesAI](https://www.youtube.com/@RobertMilesAI); subscribe to follow new videos
4. **Research papers**: read further on the specific problems
5. **Get involved**: consider contributing to AI safety research or advocacy
AI safety is an active field. This material is current as of 2026, and the research keeps moving.