Study notes Flashcards
(135 cards)
0
Q
What is data integrity?
A
Where data is correct and accurately reflects its source.
1
Q
Define collecting?
A
The process where data is entered or captured into a computer system. it includes knowing: what data is required, from where it will come and how it will be gathered.
2
Q
What is data validation?
A
A check to ensure that data is reasonable and meets certain criteria.
3
Q
What is data verification?
A
A check to ensure data collected matches the source.
4
Q
What are different hardware used for collection?
A
Microphone, scanner, keyboard, camera and OCR.
5
Q
Define software.
A
The instructions that control the hardware and its direct operation.
6
Q
What is application software?
A
A software that performs a specific set of tasks to solve specific types of problems eg. MS word.
7
Q
What is a device driver?
A
A program that provides interface between the operating systems and peripheral devices.
8
Q
What is user interface?
A
The means by which users and computer systems interact.
9
Q
What are some non-computer procedures in collecting?
A
Literature searches, surveys and interviews and manual recording.
10
Q
7 Social and ethical issues?
A
Privacy of the individual, security of data and information, accuracy of data and information, health and safety, copyright laws, changing nature of works and appropriate use of information.
11
Q
5 types of data commonly used by IS.
A
Text, numbers, video, image and audio.
12
Q
7 types of information processes?
A
Collecting, organising, processing, analysing, storing and retrieving, transmitting and receiving and displaying
13
Q
Social and ethical issues in collecting?
A
Bias in collection, accuracy of data, privacy concern for individuals, failure to acknowledge data and ergonomics for data entry participants.
14
Q
Define organising.
A
Process of arranging, representing and formatting for use by other information processes.
15
Q
What does ASCII stand for?
A
American Standard Code for Information Interchange.
16
Q
What are some common methods of organising text data?
A
DOC, PDF, TXT, RTF, HTML
17
Q
define bitmap.
A
A bitmap defines a display space and the colour for each pixel or bit in the display space.
18
Q
What is RGB.
A
This is a colour system that mixes different intensities of red, green and blue to form different colours.
19
Q
what are vector diagrams?
A
Vectors diagrams is the use of points, lines, curves and shapes to represent images in computer graphics
20
Q
What happens in sampling of sound?
A
Sampling records instantaneous amplitude at precise time intervals and the higher the sampling rate, the more accurately it reflects the sound sample.
21
Q
how is audio data organised?
A
As a series of sound samples.
22
Q
What is the difference between hypertext and hypermedia.
A
Hypertext are bodies of text or image that are linked in a non sequential manner whilst hypermedia include links to a variety of media types like images, video, audio.
23
Q
In HTML what do angle brackets signify.
A
These brackets tell us that the text enclosed is an instruction.
24
What is animation?
The process of creating and editing artificial moving images.
25
Three major functions of presentation software.
An editor that allows inserting and formatting text. A method for inserting and manipulating graphic images. A slide show system to display content.
26
Non computer tools for organising.
Hard copy systems, phone books, card catalogues, filing cabinets in office, manual and paper techniques to organise data.
27
Social and ethical issues for organising.
Cost of poorly organised data, current trends in organising data and appropriate method of organising.
28
What is analysing?
The process in which data is represented and summarised so that humans can better understand it.
29
What are hardware requirements for analysing?
Large amounts of primary and secondary storage that allows fast processing
30
What is RAM?
* Ram is a form of computer data storage
* Holds software and data used by CPU during processing
* Its memory is volatile, which means it loses all its data when the power is switched off.
* A a result files should be saved to secondary storage drives like hard disk
* Operates at far greater speeds than secondary storage
31
What is hardrive?
Hardrive is a secondary storage device that is non-volative and having 3 platters and 6 read-write heads. Data is stored on surface of platter in sectors and tracks.
32
What is a CPU?
Is the pretty of a computer system that carries out the instructions of a computer program to perform the basic arithmetical, logical, an input/output operations of the system
33
What are some software for analysing?
```
searching/selecting data
Sorting
Modelling/simulations
What-if scenarios
Charts and graphs to identify trends
File comparison
```
34
What is a model and what is a simulation?
A model is used to represent some real world systems
Purpose of a model: allowing to establish an understanding of an object
Purpose of a simulation: test a model to predict how the real object would react under different conditions e.g. training pilots using flight simulators
35
What are some non-computer tools for analysing?
Searching manual file systems, non-computer models and simulations.
36
What are non-computer models built for?
to check whether the product fulfils its objectives, test the product in real world situations, check whether the product is human friendly
37
What are reasons for maintaining manual file systems?
Cost, volume of data, training, nature of data
38
What are some social and ethical issues related to analysing?
Unauthorised analysis of data, data analysed incorrectly, erosion of privacy from linking databases for analysis
39
What is storing and retrieving?
The two step process where data or information can be saved and reloaded.
40
What is the role of storing and retrieving?
```
storing and retrieving preserves data. Reasons for preserving data are, to allow:
other processes to take place
For a temporary halt in the system
Backup and recovery
The transfer of data or information
```
41
What is virtual storage?
memory that appears to exist as main storage although most of it is supported by data held in secondary storage
42
How can data loss occur?
hard disk failure, software faults, theft, fire viruses
43
What are the two types of backup?
```
Full backup (includes all files)
Partial backup (include only the files that have been created or changed since last backup
```
44
What are the commonly used three sets of backup?
Monthly grandfather backup, weekly father backup, daily son backup
45
What is random and sequential access?
random access is also called direct access and is when data can be read or written without touching other data (when location of data is known)
Sequential access is when data must be stored or retrieved in a linear sequence
46
What are hardware used for storing and retrieving?
Magnetic disks, optical disks, flash memory, network storage and magnetic tape.
47
what are advantages of digital data?
easy to manipulate, easy to store, easy to handle, easy to transmit, cheap to handle, easy to keep up to date, fast to process.
48
disadvantages of digital data?
must be backed up to avoid loss, copyright and privacy, training of personnel, software and hardware costs and access to technology for all.
49
define users and participants.
Participants directly initiate information processes within an information system
User is a person who views or uses the information output from an IS
50
define processing,
the process that manipulates data by updating and editing it.
51
Define transmitting and receiving.
the process that transfers data within and between information systems
52
define displaying.
the process that outputs information from an IS
53
How is does RAID work?
RAID 0 is striping which is when split data into blocks/chunks and store them equally across a minimum of two separate drives.
RAID 1 is mirroring which is writing the same blocks of data onto two separate disk drives achieving 100% redundancy
54
How is data stored and accessed in flash storage?
Data is stored using electricity in surface mounted chips on a printed circuit board and it is accessed using many things like USBs
55
How is data stored and accessed on optical disks?
Data is stored on platters by a laser burning the unreflective layers under the protective surface and is accessed by a low powered laser reflecting off the surface in between.
56
How is data stored and accessed on magnetic disks?
Stores data on flat, rotating disks called platters. Spots have magnetic orientation in one direction or another. When the spots are located the read/write heads scan the spots for its magnetic properties and then sends it to the buffer as a binary sequence.
57
How is data stored and accessed on magnetic tapes?
Data is stored via a magnetic coating that is applied to a plastic strip of tape. Data is then accessed sequentially as the tape is wound up.
58
What are the software for storing and retrieving?
```
Hardware and software interface
File management software
Data base management systems
File formats for different data types
Internet browser
Encryption/password protection
Security of stored data
```
59
how does hardware to software interface work?
User interacts with the application to initiate the save --> application then notifies the OS and passes the name and location of file --> OS then directs device driver to proceed storing --> when device read to save, device driver informs OS which then informs application to send to the device driver --> device driver passes the data from application to storage device
60
what is firmware?
storage device has its own permanently stored software which is also the brain of the device. Firmware controls the mechanics of the storage device.
61
What is file management software?
Is used to logically organise files on secondary storage devices. eg. Finder, Windows explorer
62
What is database management systems?
Are software applications used to store and retrieve data within databases.
63
What is pessimistic locking?
the first user to start editing locks the record and subsequent users must wait for the updated record to be stored before they can edit
64
What is optimistic locking?
Assumes that conflicts can rarely occur. DBMS checks for record change prior to storing each record. If another user has made a change, a warning message is given and either the record can be overwritten or current changes discarded
65
What is an internet browser?
Browsers provide the interface between the user and the information in the cyberspace
66
What is single key encryption and two key encryption?
single key encryption is known as symmetrical encryption and the same key is used to encrypt and decrypt. Two key encryption is known as asymmetrical encryption and it is when the pubic key is used to encrypt and the private key is used to decrypt.
67
Non-computer tools for storing and retrieving?
Paper based storage systems, microfiche, library
68
Social and ethical issues for storing and retrieving?
security of stored data, unauthorised retrieval of data, advances in storage and retrieval technologies
69
What are software used for collecting?
collection device drivers
data entry into application software
the Internet as a collection source
70
what is bit-mapping?
the relationship between images and the bits in memory
71
What are the different types of processing?
Distributed (parallel, client-server) and Centralised
72
What are dumb and intelligent terminals?
Dumb terminals: consists of a monitor, keyboard and a connection to the central computer and is unable to do any processing.
Intelligent terminals: can do simple organising, collecting and displaying independent of the central computer, allowing it to concentrate on actual data processing
73
What is centralised processing?
a single computer performing all processing for one or more users
74
what is time sharing?
Time sharing is used by the central computer which allows multiple applications and multiple users to share processing resources of a single computer
75
What is distributed processing?
Multiple computers used to perform processing tasks.
76
What is parallel processing?
Form of distributed processing where multiple CPUs operate simultaneously to execute a single program or application.
77
What are the two main types of parallel processing?
Many CPUs contained within a single computer where they share RAM and other memory sources.
Each CPU located within a single computer.
78
What is client server processing?
A form of distributed processing where multiple CPUs operate sequentially. It has multiple computers with one acting as the server and the others as clients sending data to the server computer.
79
What are the hardware in processing CPU?
Control Unit, Arithmetic Logic Unit, Main memory, Input/output, secondary storage.
80
What are buses?
Connects the CPU with primary storage and input/output devices. Collection of wires used to move data between components.
81
What is the fetch-execute cycle?
Process used by CPU to fetch an instruction from primary storage, decode the instruction and then executes it.
82
What is search and replace operation?
Involves analysing and processing (eg replace house with home).
83
What is the purpose of spreadsheets?
To process numeric data. They use formulas to perform processing.
84
What is DBMS?
Database Management Systems is a computer program designed to manage a database and run operations on the data. eg microsoft access
85
what are the social and ethical issues of processing?
ownership of processed data and bias in the way participants in the system process data.
86
What are the data transfers within a computer?
Between RAM and CPU
When using peripheral devices e.g. keyboards printers and modems
Between computers using LAN and WAN
87
What is serial communication?
All the data bits travel in the correct order one after the other along the same connecting link eg telephone lines
88
What is parallel communication?
in parallel each data bit travels along its own connecting path eg printer
89
What is simplex, half duplex and full duplex?
Simplex is when data can only move in one direction eg keyboard
Half duplex is when data can move both ways but not at the same time eg walkie talkie
Full duplex is when data can move both ways simultaneously eg telephone
90
What is synchronous and asynchronous?
For users synchronous refers to real time communication eg telephone call
For users asynchronous refers to pauses between sending and receiving eg email
91
What are hardware for transmitting and receiving and describe each.
Buses, ports, modem, LAN, WAN,
92
What is a system bus?
A system bus is made up of the address bus, data bus and control bus. the buses are parallel links between CPU and external devices.
93
What is a port?
A port is the interface between the system data bus and external device.
94
What is data bus?
Data bus transfers data to or from the CPU. It operates in half duplex. Intended receiver depends on address and control bus.
95
What are the address and control buses?
Address bus transmits memory locations from CPU to both memory and I/O systems. It operates in simplex. CPU uses the control bus to control the operation of main memory and I/O systems. Control bus operates in full duplex.
96
What are the different ways of connection with external devices?
Serial PS2 ports, USB, Ethernet, Firewire.
97
What is a modem?
It is a communication device that converts data signals between digital and analogue.
98
What is modulation and demodulation?
Modulation is converting data signals from digital to analogue. Demodulation is converting analogue signals to digital signals.
99
What are the different types of modems?
Dial up, ADSL, cable
100
What is LAN and WAN?
Local Area Network is used to connect computers and devices that are physically close to each other. Wide Area Network connects computers over a wide geographical area. It relies on telephone lines and other data links to provide connection.
101
What is FTP client software?
Enables uploading and downloading files over the internet.
102
What are non-computer tools for transmitting and receiving?
Mail, phone, fax, radio, television
103
What are the social and ethical issues for transmitting and receiving?
Quality of data received from the internet
•Security of data being transferred
•Net-etiquette
•Acknowledgement of data source
•Global network issues, time zones, data fields, exchange rates
•Changing nature of work
•Current developments and future trends
•The impact of internet on traditional business
104
What are hardware for displaying?
LCD/CRT/Plasma screens, printers, plotters, speakers, projectors, interactive whiteboards
105
What does a video card do?
Allows the computer to send graphical information to a video display device such as a monitor or projector
106
How do CRT work?
Look up for answer...
107
How do LCD work?
Look up for answer....
108
How do plasma work?
look up for answer.....
109
How do inkjet printers work?
Shoot a stream of microscopic ink droplets onto the sheet of paper. Print mechanism moves across the paper in a series of horizontal sweeps to create a complete page
110
How do laser printers work?
Uses lasers to place dots onto a light sensitive drum. This drum is then slightly rotated and another line of dots is lasered on. These areas are charged and attract toner. This then gets pressed onto the sheet of paper and the paper passes through heat rollers to melt the toner.
111
How do plotters work?
A pen draws line across the paper which is controlled by a computer moving a bar left and right across the paper. Used to create engineer drawings.
112
How do speakers work?
Takes the electrical signal and translates it back into physical vibrations to create song waves. Includes an electromagnet made up of a coil of wire and surrounded by magnetic metal. When electric currents get sent through, creates a magnetic field. Paper diaphragm compresses and decompresses the air forming final sound waves
113
How do interactive whiteboards work?
It is connected to a computer via usb or wirelessly. Device driver installed so whiteboard can act as human input device. Computer’s video output is connected to a digital projector.
114
What are software for displaying?
Reporting within Database applications, Formatting within word processing applications, Presentation software applications
115
How do you combine information from different sources?
Embedding (copy, paste), Linking (hyperlink), mail merge
116
What are non-computer tools for displaying?
storyboards, traditional methods of display (concert, painting)
117
What are social and ethical issues of displaying?
Communication skills of those presenting displays
Past, present and emerging trends in displays
Appropriate displays for a wide range of audiences
118
When does a new information system need to be developed?
When the existing system no longer meets the needs of the users. New needs are identified that can be met by an information system.
119
What are the stages of SDLC?
Understanding the problem, planning or making decisions, designing solutions, implementing solutions, testing/evaluating and maintaining.
120
What is project management?
A methodical, planned and ongoing process that guides all the development tasks and resources throughout a project’s development
121
What are the communication skills?
Active listening, conflict resolution, negotiation skills, interview techniques and team building.
122
What are the stages of team development?
Forming, Storming(beginning to feel comfortable with each other), Norming(team members now recognise their difference), Performing
123
What are the project management tools?
Gantt chart, communications management plan, funding management plan, journals and diaries.
124
What are the social and ethical issues related to project management?
Privacy, copyright, security of data/information, providing appropriate work environment.
125
What is the deliverable for the first stage of SDLC?
Requirements report done by system analyst.
126
What are the different kinds of feasibility?
Technical, scheduling, operational, financial
127
What are the different types of system approach?
Traditional, outsourcing, prototyping, customisation, participant development, agile method
128
What are the system design tools?
Context diagram, data flow diagram, data dictionary, decision tree, decision table, storyboard.
129
What are the implementation methods?
Direct conversion, phased conversion, parallel conversion, pilot conversion
130
What is involved in the testing, evaluating and maintaining stage?
Testing involves seeing if the system meets the requirements. Evaluating seeks to see the improvements to be made to the system. Maintaining involves regularly updating software and also fixing hardware.
131
What is telecommuting and what are the disadvantages and advantages?
Telecommuting is working from home. The advantages of telecommuting include being able to work and include the chores that need to be done, being able to start earlier and finish earlier. Disadvantages include not being very formal when discussing about an important business plan that should be done in person.
132
What is the difference between social and ethical issues?
Social issues affect the way we live and work in our environment. Ethical issues affect what is right and wrong.
133
What are some differences between people centred systems and machine centred systems?
```
People Machines
"Get tired and bored
Make mistakes
slow to handle data
forget
behave intuitively
can think about the nature of work
can create new ideas and associations
need training
work best when work is meaningful
can recognise nonsensical output
```
```
Machine centred
" "Never become tired or bored
Operate consistently with programmed instructions
very fast at handling data
don’t forget
don’t act intuitively
incapable of thinking about work
don’t create any new ideas or associations
need programming once only
do not require work to be meaningful
can’t recognise nonsensical output "
```
134
What is bandwidth?
Deference between lowest and highest frequencies in a transmission channel.
