Abstract Map

Keep what matters. Remove what doesn't.

Year 8 Computer Science — Abstraction

Two Maps, One Place

Satellite Photo

✓ Real building shapes

✓ Actual road curves

✓ Trees, cars, shadows

✓ Geographically accurate

Tube Map

✓ Station names

✓ Which line goes where

✓ Interchange stations

✗ No real distances

Which would you use to find a classroom? Which to check the roof?

Abstraction

Removing unnecessary detail to focus on what matters for a specific purpose.

Same place → different abstractions for different purposes
No single "correct" level of detail
The tube map removes geographic accuracy — irrelevant to passengers
The tube map keeps connections — essential to passengers

Three Maps, Three Purposes

Satellite photo → for engineers, architects, roof inspectors
Tube map → for passengers navigating the network
Fire evacuation map → for escaping safely in an emergency

Same building. Three valid, different abstractions.

Design Challenge

Choose your purpose: Fire Evacuation | New Student Tour | Delivery Driver

Draw your abstracted map on the worksheet
Include ONLY what matters for your purpose
Justify every inclusion and exclusion

Ask: "Does a fire evacuation map need the vending machines?"

Compare Across Purposes

Find someone who chose a different purpose.

How are your maps different even though they show the same place?
What did they include that surprised you?
What did they leave out that you kept?

CS Connection

Programmers use abstraction constantly:

sort([3,1,4,1,5])  ← you don't see HOW it sorts
send_email(to, subject, body)  ← hides SMTP complexity
player.take_damage(5)  ← hides health calculation

Abstraction hides complexity behind a simple interface.

Key Takeaway

Abstraction = keep what's needed, remove what's not.

The same system can have many valid abstractions — each correct for its purpose.

Good abstraction is about choosing what to leave out.

Discussion

Is more detail always better?
Can you think of a time when too much information made something harder to use?
What real-world things use abstraction to hide complexity?