Definition
You say "Hey, play my favourite song." What happens before the music starts?
An AI system is a machine that takes in information from its surroundings (input), makes sense of it, decides what to do to reach a goal, and acts (output). Many AI systems also learn, so they improve over time.
In simple words
Think of a smart speaker. Its microphone hears your voice (perceive). It turns the sound into words and works out that you want a song (understand and decide). It plays the song (act). If you often skip a song, it learns to suggest it less (learn).
Why it matters
These parts appear in every AI system, from a robot vacuum to a self-driving car. When you meet a new AI product, you can ask: what does it sense, what does it decide, what does it do, and does it learn? Those four questions explain almost any AI system.
How it works
| Part | Job | In a smart speaker |
|---|---|---|
| Input (perceive) | Take in information through sensors | Microphone hears your voice |
| Understand | Turn raw input into meaning | Sound becomes the words "play my song" |
| Decide (reason) | Choose an action that meets the goal | Pick which song and from where |
| Output (act) | Do something in the world | Speaker plays the music |
| Learn | Improve from feedback | Notices songs you skip |
Engineers call a system like this an agent: something that senses its environment and acts in it to reach a goal.
Try it yourself
Follow your voice through a smart speaker
You say “Play some music”. Every AI system has these same parts.
What happens between your question and the answer?
Put the smart speaker's steps in the right order.
- 1The system works out what you want
- 2The sound is turned into words
- 3The microphone picks up your voice
- 4The speaker gives the answer or plays the song
- 5It learns from whether you were happy with the result
- 6It chooses the best action
Label the parts of a robot vacuum
Match each part of the robot to its job.
- Bump sensors and camera
- Map of the room in its memory
- Choosing the next spot to clean
- Wheels and brushes
Common mistakes
- Thinking AI needs a body. Many AI systems are only software, with a screen as their output.
- Forgetting the goal. An AI system always works towards a goal that people set.
- Thinking every AI system learns. Some only follow knowledge given to them.
Check yourself
Summary
- An AI system perceives, understands, decides, acts and often learns.
- Inputs come from sensors; outputs are actions or answers.
- Ask four questions of any AI product: what does it sense, decide, do and learn?
Finished reading?
Sources: Russell & Norvig, Artificial Intelligence: A Modern Approach · AI4K12: Five Big Ideas in AI