Computer Science KS3 / KS4: What is decomposition?

A teenage programmer discovers how decomposition works through trial and error.

She tries asking her computer to go shopping for her but he doesn't understand.

She realises she has to break down the task into a list of simple instructions to follow.

With a clear set of ordered instructions, the computer goes to the shop, collects the items, pays for them - but returns without them.

The programmer has forgotten to tell him to bring the shopping home in her instructions.

She amends her code, including all the necessary instructions.

These clips are from the series How to Think Like a Computer.

Teacher Notes

This could be used to explore algorithms through working out steps in a process, once this is done students could then write the algorithm out in pseudo code or as a flowchart.

This could be linked to an explanation of binary, as computers need everything broken down into simply, such as in 1’s and 0’s.

You could ask students to think of everyday situations and then write algorithms through decomposing the situation or problem.

Students could discuss the contributions of women in IT such as Ada Lovelace, as the main character is called Ada.

This could be used to discuss whether computers think?

Do humans think?

Curriculum Notes

This clip will be relevant for teaching Computer Science at KS3 and KS4 in England, Wales and Northern Ireland and National 4 and 5 in Scotland.