We all live with computers but getting the most out of them… getting them to do what you need… can be kind of difficult.
But if you can understand how they process things, a computer can be the most useful housemate you’ll ever have.
Some tasks seem very simple – like following a recipe - but even simple things can be complicated for computers. They don’t know which details are important and which aren’t. While we know the colour of an egg doesn’t matter. Computers are not that smart.
So you have work out for them what things are relevant and what can be ignored.
We call that Abstraction. But it really just means telling the computer to focus on the essentials…
Let’s say you wanted to start a dance troupe – and maybe you held the audition…at home. How would you explain to a computer who to let in and who to turn away?.. To solve this task the computer needs to be told what’s relevant and what isn’t.
You might tell it to look out for a whole load of different things… So you didn’t waste your time auditioning the wrong kind of people.
[crowd sighing]
Abstracting is working out which of those details are important.
If we don’t get it right, our algorithms won’t work properly.
To put together a dance group, what’s important is that they are willing to dance and also actually can dance. What isn’t important is what they’re wearing or the colour of their hair… That’s abstraction for you.
Ada:
Okay everybody, form the top. And one and two and four… And… Dog?
[Dog sighing]
All we need to do now is add ‘BEING HUMAN’ to the list!
Abstraction - identifying what’s important.
Video summary
A teenage programmer finds out how to use abstraction in programming.
She gives instructions to her "computer" - a human figure with a monitor for a head.
She asks him to let people in for a dance audition, only choosing those who can dance and want to dance.
Because she doesn't specify in her code that the dancers have to be human, an enthusiastic little dog is among those selected to audition.
Abstraction means telling a computer what information is important and what isn't.
These clips are from the series How to Think Like a Computer.
Teacher Notes
Discuss other situations and abstract the main parts, e.g., look at games (board or computer) and abstract the main parts.
Link to object oriented programming, hiding of data and encapsulation.
Discuss the contributions of women in IT such as Ada Lovelace as the main character is called Ada.
This clip will be relevant for teaching Computer Science at KS3 in England, Wales and Northern Ireland and 3rd Level in Scotland.
Algorithms. video
Why do computer programs use algorithms?
What is decomposition? video
A teenage programmer discovers how decomposition works through trial and error.
Pattern Recognition. video
A teenage programmer is giving her computer instructions on making a sandwich.
