unit 10

Question 1

define computational thinking

Answer 1

the ability to think logically about a problem and apply techniques to solve it

Question 2

what is abstraction?

Answer 2

the process of removing unnecessary details of a problem to focus on the important features to implement in a solution

Question 3

what are some real life examples of abstraction?

Answer 3

a car simulator, a representation of a building, a map of a train route

Question 4

what are preconditions?

Answer 4

conditions that must be true for an algorithm to complete successfully without errors or crashing

Question 5

what are some examples of preconditions?

Answer 5

parameter list must not be empty
data needs to be of the same type

Question 6

what is the process for defining preconditions?

Answer 6

Name
Inputs
Outputs
Preconditions

Question 7

what are the advantages of specifying preconditions?

Answer 7

if provided in documentation, then the developer is aware of what checks are required
allows the subroutine to be reusable and put in a library to be called whenever

Question 8

what is caching?

Answer 8

cache is tiny storage on a processor used to temporarily store frequently used data

Question 9

what is web caching?

Answer 9

HTML pages and images most recently looked at are stored for faster access and saving bandwidth by not requiring them to be redownloaded each time

Question 10

what is the need for reusable components?

Answer 10

commonly used subroutines are bundled into libraries
already tested
save time with new projects

Question 11

what is decomposition?

Answer 11

the process of breaking down into smaller sub problems until each module can be tackled individually

Question 12

what is a top down design?

Answer 12

breaking down problem into smaller ones until each one is unable to be broken down further

Question 13

what is the goal of a top down design?

Answer 13

to structure a program into small manageable tasks

Question 14

what is the advantage of decomposition?

Answer 14

each subroutine is simpler to test and maintain (unit testing)
each subroutine is self-contained and well documented it is easier to find errors in code
can reuse the subroutines

Question 15

what is unit testing?

Answer 15

checking the smallest building blocks of your code to ensure they work perfectly

Question 16

what is a hierarchy chart?

Answer 16

a diagram used to show problem decomposition
they show how module and subroutines relate to each other like a tree structure

Question 17

what is sequence?

Answer 17

one statement after another

Question 18

what is selection?

Answer 18

decision making

Question 19

what is iteration?

Answer 19

loops

Question 20

what are the purpose of programming techniques?

Answer 20

to aid the readability, understanding and maintainability of code

Question 21

what do decisions affect?

Answer 21

decisions are Boolean conditions in selection or iteration which affect the flow of control in a program

Question 22

what is the difference between branching and iteration?

Answer 22

branching involves directing the flow of control of a program dependent on a Boolean condition
iteration involves repeating a sequence of instructions based on a stopping condition

Question 23

what is concurrent computing?

Answer 23

allows multiple processes to run on a single processor by giving each process a fraction of time and control over the processor before swapping processes

Question 24

what is parallel computing?

Answer 24

where multiple processes are run at the same time over multiple processor cores to enable faster execution

Question 25

what is a batch program?

Answer 25

executing a series of computer program or tasks without requiring user interaction during their execution

Question 26

what are the advantages of concurrent processing?

Answer 26

increased program throughput as the number of tasks completed in a timeframe are increased time spent waiting for user input is minimised by swapping to another task

Question 27

what are the disadvantages of concurrent processing?

Answer 27

if large numbers of processes are running, high computation is needed, these processes will take longer to complete as each is allocated a certain time slice overhead in coordinating and switching between processes

Question 28

what are the advantages of parallel processing?

Answer 28

when performing repetitive calculations on large data, can speed up performance by splitting processes over processors graphical processing units can render 3D objects quickly by splitting the computations

Question 29

what are the disadvantages of parallel processing?

Answer 29

different processors running programs at the same time may need to communicate leading to overhead some tasks may run faster or be optimised to run on a single processor rather than multiple