Computational methods

Question 1

What is meany by a computable problem?

Answer 1

A problem that can be solved using an algorithm

Question 2

Give 3 limiting factors to computable problems

Answer 2

• Processing power
• Processor speed
• Computer memory
• Time

Question 3

State 2 factors which may be considered during the problem definition phase

Answer 3

• Strengths and weaknesses of current solution

- Volume/type/frequency/nature of: inputs, outputs, stored data

Question 4

What is the name given to the process in which problems are continually broken down until each subproblem can be represented as a subroutine?

Answer 4

Problem decomposition

Question 5

State 2 purposes of problem decomposition

Answer 5

• Identify sections which can make use of pre-coded modules or libraries
• Save time coding
• Simplify project management
• Simplify testing and maintenance
• Faster project delivery
• Develop sections in parallel

Question 6

Describe how the divide and conquer technique works

Answer 6

• The problem size if halved with every iteration
• Each individual subproblem is then solved recursively
• The solutions to the subproblems are then recombined to form the final solution to the problem

Question 7

Give 2 applications of divide and conquer

Answer 7

• Merge sort
• Binary search
• Quick sort

Question 8

Which programming construct do many problems solve using divide and conquer use?

Answer 8

Recursion

Question 9

What is representational abstraction?

Answer 9

A computational technique in which excessive details are removed to simplify a problem

Question 10

What type of abstraction is used to group together sections of the problem based on their functionality?

Answer 10

Abstraction by generalisation

Question 11

State 2 problem solving techniques

Answer 11

• Backtracking
• Data mining
• Abstraction
• Divide and conquer
• Visualisation
• Performance modelling
• Pipelining

Question 12

What is meant by heuristics?

Answer 12

Heuristics are a non-optimal, ‘rule-of-thumb’ approach to problem-solving which are used to find an approximate solution to a problem when the standard solution is unreasonably time-consuming or resource-intensive to find

Question 13

What is meant by performance modelling?

Answer 13

• Provides mathematical methods to test a variety of loads on different operating systems
• Performance modelling provides a cheaper, less time-consuming, safer method of testing applications

Question 14

Describe how backtracking works

Answer 14

• The backtracking algorithm works by methodically visiting each path and building a solution based on the paths found to be correct
• If a path is found to be invalid at any point. it backtracks to the previous stage and visits an alternate path

Question 15

When might heuristics be used in problem-solving?

Answer 15

When the standard way to solve the problem is unreasonably time-consuming or resource-intensive

Question 16

State 2 advantages of using performance modelling

Answer 16

• Safe
• Relatively inexpensive
• Less time-consuming

Question 17

What is pipelining?

Answer 17

• A process in which tasks are developed in parallel

- The output of one process in pipelining becomes the input of another, resembling a production line

Question 18

What is the name given to the technique used to identify patterns and trends in large sets of data?

Answer 18

Data mining

Question 19

What is meany by data mining?

Answer 19

• Data mining is a technique used to identify patterns or outliers in large sets of data, termed big data
• Data mining is used in software designed to spot trends or identify correlations between data which are not immediately obvious