2.1 Computational thinking

Question 1

What is meant by the term ‘abstraction’ (2)

Answer 1

Removal of unnecessary detail…
… to allow programmers to focus on key features of the problem…
…simplifies a complex problem

Question 2

Give three benefits of using abstraction when writing a program

Answer 2

Reduces programming time
Reduces complexity of code
Reduces amount of computational power
Make the problem easier to solve

Question 3

What is thinking ahead

Answer 3

• Recognise the required input and output
• preconditions
• caching
• reusable program components

Question 4

What is meant by ‘concurrent processing’ (2)

Answer 4

Processes happen at the same time.
One process can start before another one finishes.
Each processes is given a slice of processor time.

Question 5

Is concurrent processing same as parallel processing?

Answer 5

No.
Concurrent processing is when tasks are given a slices of processor time, to give the illusion that tasks are being performed simultaneously. - in reality they are executed sequentially.
Parallel processing is when multiple processors are used to complete more than one task simultaneously.

Question 6

Benefits of concurrent processing (2/3)

Answer 6

More efficient processor use
Tasks requiring preconditions can wait and then resume execution
User is able to interact with the computer while other tasks are running

Question 7

Drawbacks of concurrent processing

Answer 7

Can take longer to complete when large numbers of users or tasks are involved.
Overhead
Not all tasks are suited to being broken up and performed concurrently.