Software Design and Development

Question 1

What are the phases of an iterative development process?

Answer 1

(A Dance In The Dark Every Monday)
Analysis – production of a software specification that will outline what the software must do
Design – plan the design of the program, and the user interface
Implementation – write the code for the program/ software
Testing – fully test the program/ software to ensure that all aspect work correctly
Documentation – technical guide – how to install software - and user guide – how to work the software.
Evaluation – is the program fit for purpose and robust
Maintenance- keep checking up on the program to ensure it continues to run smoothly.

Iterative process – each stage may have to be revisited.

Question 2

what are the inputs,processes and outputs of a program?

Answer 2

Inputs – data that is entered into the program.
Processes – what the program does with the inputted data.
Output – data that is outputted to the user.

Question 3

what is the purpose of a structured diagram?

Answer 3

It breaks the problems down into smaller sections.

Question 4

what is the purpose of a flowchart?

Answer 4

It shows what is going on in a program and how data flows around it.

Question 5

what is the pseudocode?

Answer 5

Its structured English for describing a program, read by a human

Question 6

What is the symbol used for an input or output in a flow chart?

Answer 6

___
/___/
a parallelogram

Question 7

What is the symbol used for data flow (direction of data flow) in a flow chart?

Answer 7

➞

an arrow

Question 8

What is the symbol used for decisions(yes or no)in a flow chart?

Answer 8

🔸

a diamond

Question 9

What is the symbol used for a process in a flow chart?

Answer 9

ㅁ

a rectangle

Question 10

What is the symbol used for a process in a structured diagram?

Answer 10

ㅁ

a rectangle

Question 11

What is the symbol used for a loop in a structured diagram?

Answer 11

⬭
an oval (ellipse)

Question 12

What is the symbol used for a selection in a structured diagram?

Answer 12

__

a pointy edge oval.

Question 13

What is the symbol used for a Pre-defined function in a structured diagram?

Answer 13

_____
||__||
a rectangle with two extra lines at the end.

Question 14

list all of the data types and their uses.

Answer 14

string – stores text and alphanumeric combinations e.g. Sausage, AB12 4RT
character – stores a single character which can be a letter, number or symbol e.g. Q. #, 6
integer – stores positive and negative whole numbers e.g. 17. -45. 124
real – stores numbers with decimal places, can also store integers e.g. 3.14, - 5.67
boolean – stores TRUE or FALSE only.

Question 15

name a data structure.

Answer 15

an array – stores a list of related data e.g. names of pupils in a class.

Question 16

How would you add A and B together?

Answer 16

a + b

Question 17

How would you takeaway B from A?

Answer 17

a – b

Question 18

How would you times A and B?

Answer 18

a * b

Question 19

How would you divide A by C?

Answer 19

a / c

Question 20

How would you put A to the power of B (exponentiation ) ?

Answer 20

a^b

Question 21

what is the process of joining two or more strings together to make a new text string?

Answer 21

concatenation- represented by “&” in pseudocode and “,” in python

Question 22

Name and describe the three types of tests.

Answer 22

Normal – data that you would expect to work or be accepted (value within the range)
Extreme – data at the lower and upper limits of what is expected (lowest value or highest value in range)
Exceptional – data that should not be accepted by the program (value outside of the range)

Question 23

What are the three types of errors?

Answer 23

Syntax – This is an error in the spelling or grammar used when coding.
For example, misspelt command words, missing brackets, commands or colons.
Syntax errors are identified by the interpreter, as the code will not run.

Execution – This type of error occurs when the program is asked to do something that it cannot, resulting in a crash. For example, dividing by zero or trying to store a string a integer variable.

Logic – This is an error in the logic of the code e.g. using a < instead of >. The program will run, but it will produce unexpected results. Logic errors are usually only resolved by carrying out testing.

Question 24

How can you tell if a program is fit for purpose?

Answer 24

If it does what it is supposed to do

Question 25

Efficient use of coding constructs

Answer 25

use of loops –repeating instructions is more efficient than a sequence of individual instructions.
arrays – using arrays to store related data is more efficient than using multiple variables.
nested IFs – using IF … ELSE IF … is more efficient that using multiple IF … THEN

Question 26

is the program robust?

Answer 26

can the program cope with unexpected input or mishaps without crashing
usually programs made at Nat 5 level are not fully robust.

Question 27

How do you tell if a program is readable?

Answer 27

if it has:
internal commentary – add descriptions, notes and explanation to the code.
meaningful identifiers – use variable names that describe what the variable contains.
indentation – makes it easier to identify constructs. Mandatory in Python.
white space – help makes it clearer where code is placed.