2. Designing Computer-Based Information Systems

Question 1

What are the three most common types of processing systems? (Operational modes)

Answer 1

Batch, interactive and real time.

Question 2

What is batch processing?

Answer 2

Process batches of data at regular intervals. Usually a large amount of data. No user interaction needed. Usually done over night or weekends. Delay between collecting data and receiving output. The UI requirements tend to be code based.

Question 3

Describe a payroll.

Answer 3

Most common use of a batch processing system. Each pay date, the details for each employee are collected. Such as hours worked, overtime, etc. These details are processed with reference to a master file with deductions on. The output is the payslip.

Question 4

What is interactive processing? (Transactional processing system)

Answer 4

Handles transactions one at a time. Each transaction must be fully processed before it moves on. Small amount of data. Usually entered with a form on the screen, input method being keyboard. Example is booking tickets - no risk of double booking as each transaction is dealt with in turn.

Question 5

Describe the process of interactive processing.

Answer 5

The user answers predefined questions on an input form which is displayed on a GUI. Database is then searched based on the responses. The results are shown on the screen. Questions/responses are in a structured fixed format.

Question 6

What is real time processing?

Answer 6

Processes data at the time the data is input. It must be handled within a specified maximum time limit. Response time usually less than 4 seconds. Generally accepted as being one that reacts fast enough to influence behaviour in the outside world.

Question 7

What is an example of real time processing?

Answer 7

An air traffic control system. Also found in embedded applications (systems within another system) such as mobile phones.

Question 8

What is an operating system?

Answer 8

Software that is responsible for allocating various system resources, such as memory, processor time and peripheral devices (printer, monitor.)

Question 9

Name 7 types of OS?

Answer 9

Single user, multi user, multi tasking, interactive, real time, batch processing and distributed processing.

Question 10

Describe a payroll.

Answer 10

Most common use of a batch processing system. Each pay date, the details for each employee are collected. Such as hours worked, overtime, etc. These details are processed with reference to a master file with deductions on. The output is the payslip.

Question 11

What is a single user OS?

Answer 11

Provides access for one user at a time. Can support more than one account but only one can be used at once. Must log off account before another can log in.

Question 12

What is a multi user OS?

Answer 12

Lets more than one user access at same time. Usually provided by a network. Common setup is a network with a single user OS connected to a server that has a multi user OS.

Question 13

What is a multi tasking OS?

Answer 13

Involves the processor carrying out more than one task at a time. The processor doesn’t usually control two things at once, it switches between.

Question 14

What is an interactive OS?

Answer 14

One where there is direct user interaction while a program is running?

Question 15

What is a real time OS?

Answer 15

One that has been developed for real-time applications. Typically used for embedded applications.

Question 16

What is a batch processing OS?

Answer 16

Given a set of tasks to run without any user intervention.

Question 17

What is a distributed processing OS?

Answer 17

Comprised of a number of computers connected together. Each computer completes part of the processing.

Question 18

Name the 6 main things a designer must consider when a human-computer interface (HCI) is being designed?

Answer 18

Use of colour, layout, quantity of information on the screen, font size, complexity of language, type of controls.

Question 19

What are the four main features of interaction between a computer and a person?

Answer 19

Prompts, nature of input, methods of input, feedback.

Question 20

What are prompts?

Answer 20

Most commonly used in a command line interface. Indicates the user needs to input an appropriate command. In a GUI, prompts are simple such as a dustbin for deleting or an X to close the window.

Question 21

What is the nature of input?

Answer 21

Interactive interfaces decide the nature of the next user input (by asking a question or requiring a selection to be made) based on the response to the previous input.

Question 22

What is the method of input?

Answer 22

For example: Keyboard/mouse.

Question 23

What is feedback?

Answer 23

Any dialogue must provide feedback. This could be in the form of menus that provide options for the user to select. A menu option may be a sub menu.

Question 24

Describe a users perception.

Answer 24

Most users will have preconceived ideas that they will draw on when using the interface, such as red meaning bad. The use of sounds are almost important. Happy sounds = using system right.

Question 25

Describe a users attention.

Answer 25

Most users have a limited attention span. The most important information should stand out so the user can see it quickly. Use of pop up messages can also help keep attention. You don't want to overdo it with extras though.

Question 26

Describe a users memory.

Answer 26

Use a consistent and uncluttered page layout so that users can remember where everything is. This will also help increase the speed at which the user learns to use the interface.

Question 27

Describe a users learning ability.

Answer 27

The designer must take into consideration how easy an interface is to learn. Achieved by using consistent layouts. On screen help in the form of HELPFUL pop up messages.

Question 28

What are the two main types of computer system users?

Answer 28

Those who have some understanding and those who have little or no understanding.