A map of the bus, not the bus
A bus map shows the stops and the routes. It does not show the seats, the paint or the bus number plate.
The map leaves out almost everything, and that is why you can read it. A support technician does the same with a failed login. They keep what helps and drop what does not.
By the end of this lesson
Note
I can use abstraction (keeping what matters) to list what a solution needs, what changes and what stays the same.
Key words
| Word | What it means |
|---|---|
| Abstraction | Keeping the details that matter and hiding the rest |
| Filter | Remove what you do not need |
| Input | Information that goes in |
| Output | Information that comes out |
| Variable | A value that can change |
| Constant | A value that stays the same |
| Internal working | How a part does its job inside |
The cells students fill in are left blank in this preview.
Starter
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Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Abstraction removes the noise
The purpose of abstraction is to make a problem simple enough to think about. A ticket might hold 40 facts. Only a few help you fix it.
Abstraction has three tasks. Identify the information you need. Filter out what you do not need. Hide the internal workings of parts you only need to use.
Three tasks, one ticket
| Task | Example: "I cannot log in" |
|---|---|
| Identify information that is needed | Username, error message, time, device |
| Filter out unnecessary details | The colour of the laptop, what the user had for lunch |
| Hide the internal workings | You use the login system without knowing how it stores passwords |
The cells students fill in are left blank in this preview.
Check
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Check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.