topic: computational thinking

Question 1

What computational method is being defined in the following?
“It involves filtering out, or essentially, ignoring, the characteristics that we don’t need in order to concentrate on those that we do. i.e ignoring the irrelevant details of any given problem”

Answer 1

Abstraction

Question 2

What are reasons for abstraction

Answer 2

• Reduces design and programming time
• Reduces complexity of a program / easier to read and understand
• Focus on the main purpose of the program

Question 3

what are the 5 main parts to computational thinking

Answer 3

thinking abstractly
thinking ahead
thinking procedurally
thinking logically
thinking concurrently

Question 4

what does thinking abstractly mean

Answer 4

Hiding details and identifying and highlighting key elements

Question 5

what does thinking ahead mean

Answer 5

What inputs / outputs will you need

Question 6

what does thinking procedurally mean

Answer 6

Order of events / subproblems

Question 7

what does thinking logically mean

Answer 7

Decisions to be made

Question 8

what does thinking concurrently mean

Answer 8

What can be done at the same time

Question 9

what are the two types of abstraction

Answer 9

1. data abstraction
   variables: represent real-world values e.g “Anna”, or “21/01/2019”
   objects: in Object Oriented Programming (OOP) a class is an abstract representation of something with attributes and methods e.g a dog or person
   Data structures: arrays, stacks and queues
2. problem abstraction
   when faced with a problem deciding which factors are relevant to the problem and solution e.g
   networks, database systems (E-R diagram), operating systems (device drivers, flight simulator, weather system, GPS

Question 10

for thinking procedurally

what are the advantages for a top down design

Answer 10

1. the problem is easier to understand, program, test and maintain
2. shows clearly how different parts of the problem relate to each other
3. division of labour - different teams working on different parts of the problem independently
4. may make code more modular as it broken into smaller subroutines

Question 11

for thinking procedurally

what are the disadvantages for a top down design

Answer 11

1. it assumes that the whole solution to the problem is knowable in advance
2. poorly understood programs are hard to decompose
3. not every problem can be broken down in this way, for example event driven programs like GUIs

Question 12

identify 3 reasons why abstraction is needed in a rail network program

Answer 12

• reduces processing requirements
• simplifies programming
• reduces memory requirements