Category: Information System Design and Development

Higher – Contemporary Developments (Revision)

Exemplification of trends in the development of:

  • Software Development Languages: use of pre-processors (allow a programmer to implement code in a language that will be translated into another before becoming machine code); use of frameworks (provides a pre-generated set of code programmers can use for design); app development (web apps used to handle different operating systems, software development kits used to create one app that can be changed for different operating systems); HTML5 (latest version of HTML)
  • Software Development Environments: use of text editors, graphical user interface creation, de-bugging tools, collaboration tools and the cloud, emulators and mini development environments via browser software
  • Intelligent Systems: designed to demonstrate aspects of human intelligence by using a computer system to replicate human decision making and interaction; key features include ability to learn, ability to make decisions without human input, presence of several aspects of human intelligence
  • Online Systems: a system that is interactive (server and client communicate and update data) and fully functional in real time when accessed via the Internet; A ticket ordering web based system or an online shopping site are examples of common online systems

Higher – Development Methodologies (Revision)

  • Rapid Application Development: means that the users should be involved at all stages of the development process and that changes to the design can be made at any time throughout the life of the project; it also means that the development process is faster and more flexible; emphasis is on creating software quickly and efficiently
  • Top-Down/Step-wise refinement: breaking down a problem into smaller more manageable steps

1 Setup Variables

2 Initialise Values
3 Do Calculation

1.1 Create number1 as a global variable
1.2 Create number2 as a global variable

2.1 Set number1 to 0
2.2 Set number2 to 0
2.3 Set total to 0

3.1 Receive number1 from keyboard
3.2 Receive number2 from keyboard
3.3 Set total to number1 + number2

  • Agile Methodologies: a product of RAD; emphasis on small scale developments, and with teams of people who have a flexible approach to change in requirements; it is important to keep the client involved in the process; there should be daily meetings between the clients and the developers, and necessary changes made to the requirements even late in development

Thank you to C O’Toole & A Madill from Braidhurst High School for allowing me to edit and publish this here.

Higher – Design Notations (Revision)

Make sure you read the N5 post on design notations for examples of Structure Diagrams, Flow Charts and Pseudocode.

Wire-Framing: A wireframe can show how a website will look and how its navigations structure works; can be as simple as a rough sketch or can be a detailed design showing colour combinations and images

Entity Relationship Diagrams

Relationships can be represented graphically using an Entity-Relationship (ER) diagram.

There are many different notations for ER diagrams, we will use crow’s foot notation.
• The names of entities are written in boxes joined by straight lines.
• At the “many” end the line forks.
• At the “one” end the line it judt joins the box.

ERD

Data dictionaries

A data dictionary is a design notation used to show the fields required in each table of a relational database, including field types, validation required, etc.

dd

Thank you to C O’Toole & A Madill from Braidhurst High School for allowing me to edit and publish this here.

National 5 – Design Notations (Revision)

N4

  • graphical to illustrate selection and iteration
  • other contemporary design notations

N5

  • pseudocode to exemplify programming constructs other contemporary design notations

 

Flow Chart
Flow Chart

You read a flow chart from the START block and follow the arrows (normally downward). In the example above you can see selection taking place in the first diamond, while the second diamond allows for iteration (repetition) to take place.

Structure Diagram
Structure Diagram

A structure diagram shows how the program is structured and in some cases how data can be passed from one part to the other.

Pseudocode

Pseudocode is an informal text description of the working of a program it is written using English words but not in a sentence structure. There are no syntax rules due to its informal nature, sometime they are numbered and sometimes they are not.

The SQA can sometimes refer to pseudocode in the exam when describing a program. However, they are often referring to Standard Reference Language. Rule of thumb, if they are asking you to read pseudocode it will be SRL, if they are asking you to write psuedocode then they mean psuedocode. Hopefully they will start using the correct terms in future papers.

Example 1

  1. set total = 0
  2. set count =0
  3. while count less than 10
  4.     get nextInput from user
  5.     add nextInput to total
  6.     add one to count
  7. end while
  8. display total/10

Example 2

get age from user
while age < 0 or age >130
    display error
    get age from user

display age

Internet 101

Quite a few students have been asking for a better explanation of how the Internet works. This sequence of videos takes you through all areas and aspects of the Internet. If you have a Khanacademy account (you do S4) then you can even earn a badge for watching the videos.

It is well worth a watch for National 4,5 & higher and it will now be making up part of our future courses.

Higher – Responsive web design in PagePlus X8

Not everyone uses a desktop computer to view web pages. A significant proportion of the population now uses mobile devices to view websites. This means that designers have to use a website design that can respond to these devices by changing page size, position of elements, etc. Normally this would be done with CSS scripting however the process is slightly different in WebPlus.

Creating the binary background

I’ve changed my background from a stock internet photo to one I created myself.

First of all I wrote a little python program that generated a random 0 or 1

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import random
message=""
for item in range(3000):
    number=random.randint(0,1)
    message=message + str(number)

print(message)

 

blueBinaryI then took a screenshot of the resulting console window and cropped it with IrfanView. I made a negative of the image and swapped the RGB colours before saving it as a PNG file.

I then uploaded the file and set it as a time background, it needs a little crop as it’s a couple of pixels too wide on one edge.

I’m sure you can think of a way that you could use this technique to create even better backgrounds with patterns or hidden messages.