2.1 Elements of computational thinking

Question 1

Define computational thinking

Answer 1

The ability to think logically about a problem and apply techniques for solving it

Question 2

Define Abstraction

Answer 2

The process of removing unneeded complexities, which creates a more generalised solution that is more useful. Reduces computational resources required. Focus on the main purpose of program

Question 3

What is the need for abstraction?

Answer 3

Saves memory and resources: Large amount of irrelevant data, that would prevent the most efficient and general solution being found

Question 4

Give some examples of abstraction (3)

Answer 4

Replacing complex objects with simple ones (like shapes)
Removal of scenery
Places can be represented by shapes with names

Question 5

Define thinking ahead

Answer 5

The process of identifying the inputs, outputs and preconditions of a program

Question 6

What are the advantages of defining preconditions

Answer 6

advantages of defining preconditions
Makes program components reusable, cuts out unnecessary checks, makes program easier to debug and maintain

Question 7

What is the need for reusable program components

Answer 7

Saves time and money, pre-written code will be well tested and bug free, inputs outputs and preconditions already specified

Question 8

Define caching

Answer 8

Saving Data and instructions that are frequently accessed in case they are needed again. Allows for faster access in future

Question 9

What are some advantages of web caching

Answer 9

Faster access to cached resources, saves use of bandwidth, reduces load on web server

Question 10

What are some disadvantages of web caching

Answer 10

May cause user to view “stale” copies of the website, takes up space on the hard drive

Question 11

What are some programming standards

Answer 11

Inputs outputs and preconditions should be documented, variable identifiers should conform to a standard convention, all variables should be local to the module, documentation should be in a standard format, code should be commented, no module > one page

Question 12

What makes a problem solvable by computational methods **

Answer 12

Involves calculations, has inputs processes and outputs, involves logical reasoning

Question 13

Define thinking procedurally

Answer 13

The process of identifying the subprocedures necessary to solve a problem

Question 14

Define decomposition

Answer 14

The process of breaking done a larger problem into several smaller problems that are easier to solve

Question 15

Define structured/ modular programming

Answer 15

Uses top-down analysis for problem solving, identifying major tasks and breaking them down into subtasks, Tasks and subtasks are written as separate, self contain modules using local variables, Uses selection iteration and sequence (structured code)

Question 16

Define modularisation

Answer 16

Breaking down of a program into several blocks of self contained code called modules

Question 17

What are the benefits of modularisation

Answer 17

Programs are more reliable and have few errors, programs take less time to test and debug, programs are easier to maintain, modules can be reused, several programmers can work on the same program at once

Question 18

What is a system diagram

Answer 18

One in which a program is broken down into its subprocedures which are then broken down into their subprocedures etc

Question 19

Define thinking logically

Answer 19

The process of deciding and identifying where decisions should be or are made in a program

Question 20

Define decision points

Answer 20

Points in a program where a decision is made based on a condition that affects the flow of a program

Question 21

How do decisions affect the flow of a program

Answer 21

Different decisions are made based on conditions. Different decisions case different outcomes, affecting the flow of the program

Question 22

Define thinking concurrently

Answer 22

The process of identifying multiple tasks that can be done at the same time

Question 23

Define concurrent processing

Answer 23

One process does not have to finish before the other starts.
Processes are happening at the same time.
Each process given a slice of processor time.
Gives the appearance that several tasks are being performed simultaneously, even though only one processor is being used

Question 24

Define parallel processing

Answer 24

Multiple processors each executing different instructions simultaneously, with the goal of speeding up computations. Impossible on a single processor

Question 25

What are the benefits of concurrent processing

Answer 25

Faster program throughput on average, lower processor downtime

Question 26

What are the downsides of concurrent processing

Answer 26

Slow down when many tasks are being requested at the same time, takes longer to finish a single part in isolation