Study notes Flashcards
What is data integrity?
Where data is correct and accurately reflects its source.
Define collecting?
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.
What is data validation?
A check to ensure that data is reasonable and meets certain criteria.
What is data verification?
A check to ensure data collected matches the source.
What are different hardware used for collection?
Microphone, scanner, keyboard, camera and OCR.
Define software.
The instructions that control the hardware and its direct operation.
What is application software?
A software that performs a specific set of tasks to solve specific types of problems eg. MS word.
What is a device driver?
A program that provides interface between the operating systems and peripheral devices.
What is user interface?
The means by which users and computer systems interact.
What are some non-computer procedures in collecting?
Literature searches, surveys and interviews and manual recording.
7 Social and ethical issues?
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.
5 types of data commonly used by IS.
Text, numbers, video, image and audio.
7 types of information processes?
Collecting, organising, processing, analysing, storing and retrieving, transmitting and receiving and displaying
Social and ethical issues in collecting?
Bias in collection, accuracy of data, privacy concern for individuals, failure to acknowledge data and ergonomics for data entry participants.
Define organising.
Process of arranging, representing and formatting for use by other information processes.
What does ASCII stand for?
American Standard Code for Information Interchange.
What are some common methods of organising text data?
DOC, PDF, TXT, RTF, HTML
define bitmap.
A bitmap defines a display space and the colour for each pixel or bit in the display space.
What is RGB.
This is a colour system that mixes different intensities of red, green and blue to form different colours.
what are vector diagrams?
Vectors diagrams is the use of points, lines, curves and shapes to represent images in computer graphics
What happens in sampling of sound?
Sampling records instantaneous amplitude at precise time intervals and the higher the sampling rate, the more accurately it reflects the sound sample.
how is audio data organised?
As a series of sound samples.
What is the difference between hypertext and hypermedia.
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.
In HTML what do angle brackets signify.
These brackets tell us that the text enclosed is an instruction.
What is animation?
The process of creating and editing artificial moving images.
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.
Non computer tools for organising.
Hard copy systems, phone books, card catalogues, filing cabinets in office, manual and paper techniques to organise data.
Social and ethical issues for organising.
Cost of poorly organised data, current trends in organising data and appropriate method of organising.
What is analysing?
The process in which data is represented and summarised so that humans can better understand it.
What are hardware requirements for analysing?
Large amounts of primary and secondary storage that allows fast processing
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
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.
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
What are some software for analysing?
searching/selecting data Sorting Modelling/simulations What-if scenarios Charts and graphs to identify trends File comparison
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
What are some non-computer tools for analysing?
Searching manual file systems, non-computer models and simulations.
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
What are reasons for maintaining manual file systems?
Cost, volume of data, training, nature of data
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
What is storing and retrieving?
The two step process where data or information can be saved and reloaded.
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
What is virtual storage?
memory that appears to exist as main storage although most of it is supported by data held in secondary storage
How can data loss occur?
hard disk failure, software faults, theft, fire viruses
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
What are the commonly used three sets of backup?
Monthly grandfather backup, weekly father backup, daily son backup
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
What are hardware used for storing and retrieving?
Magnetic disks, optical disks, flash memory, network storage and magnetic tape.
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.
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.
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
define processing,
the process that manipulates data by updating and editing it.
Define transmitting and receiving.
the process that transfers data within and between information systems
define displaying.
the process that outputs information from an IS
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