the nature of data and information Flashcards
what is data
is the raw material entered into an information system. It is the input of the system.
what is the data types?
Images are data in the form of pictures, such as drawings, paintings or photographs. They can be stored, edited and transferred in similar ways to text. The meaning of an image is determined by looking at the image and interpreting it.
Audio is data in the form of sounds. It may be a noise used to get a user’s attention or a voice to explain the operation of a piece of software. The meaning of audio data is determined by listening to and interpreting the sounds.
Video is data in the form of pictures and sounds combined and displayed over time. It may include text, graphics, animation and audio. The meaning of video is determined by watching and listening to it over a period of time.
Text is data in the form of letters, numbers and other characters whose meaning and format is not specified. For example, the characters entered into a word processor are text. The meaning of text is determined by reading and interpreting it.
Numbers are data in the form of predefined characters (usually numerals) whose meaning and format are specified. Calculations are often performed on this data type. For example, numbers may be defined as currency, date or time.
what is information
Information is data that has been ordered and given some meaning. It is the output of the system.
information must be presented in a way that…
information must be presented in a way that is attractive and easy to read. A format needs to be chosen that is appropriate for the end users of the information.
what is security of data?
The security of data and information is a major issue in any organisation. The cost of replacing data that is deliberately or accidentally damaged or lost can be enormous. People who gain illegal access to information systems are referred to as hackers. Hackers are often involved in information theft or financial theft. Information theft involves stealing data from one organisation and selling it to another organisation. Financial theft involves illegally transferring money from one account to another.
list data security involves a series of safeguards to protect the data from deliberate or accidental damage.
Passwords are secret words or numbers that are typed on the keyboard to gain access to a computer system. Good data protection systems require users to change their passwords often, so that only authorised people can have access to certain data.
Objects such as a key, plastic card or badge can be required to gain access to the information system. They are often used together with a personal identification number (PIN).
Biometric devices are used to verify personal characteristics such as finger- prints, hand size, signature, eye and voice.
Data encryption is used to prevent data from being intercepted and read during transmission. The data is ‘scrambled’ so that it is meaningless to anyone other than the recipient, who uses the same encryption software to convert it back.
Firewalls are used on computer networks to check all data coming from outside sources (such as the Internet) for the purpose of verification and authentication.
Waste is secured, since discarded printouts are potential sources of confidential information. This kind of waste can be secured by shredding.
Backup procedures need to be secure and reliable. A regular plan of copying and storing data will guard against data loss. It is good practice to keep at least one backup copy in a fireproof safe or off-site.
The weakest link in the security of any information system is the people in it. Employees need to be carefully screened. This can be difficult, as even well- respected and otherwise honest employees can commit computer crimes.
what is data validitaion?
Data is collected to solve problems, meet needs or help in decision-making. The accuracy of the data must be checked before it is processed into information. This is called data validation.
Data validation can be built into a soft- ware application. provide some example of that?
Range checks are used if the data is restricted to a small range of particular values. For example, when a date is entered in the format 21/2/2001, the software can check whether the first two digits are in the range of 1 to 31 and the second two digits are in the range of 1 to 12.
List checks are used when the data can be compared to a set of accepted data. For example, when the data entered is an Australian state, NSW would be accepted but NSX would not.
Type checks are used to determine whether the data type is correct. For example, when the data entered is a person’s family name, the software can check if the data is text. It would not accept other data types, such as numbers.
A check digit is a number calculated from the digits of a code number and then added to that number as an extra digit. The ISBNs (International Standard Book Numbers) given to books include a check digit. For example, in the ISBN 0 85859 921 4, the final 4 is a check digit. It is calculated by applying a formula to the other numbers (085859921).
what is copyright?
Copyright is the right to use, copy or control the work of authors and artists, including software developers. It is often indicated by the © symbol. Copyright is protected by law. In Australia, the Copyright Act regards any original work as the intellectual property of the person who created the work. Copyright ownership is automatic and applies whether or not the work is accompanied by the copyright symbol. Most other countries have similar laws and have signed international copyright agreements. It is against the law to use or copy the work of another person without their permission. There are some exceptions. For example, you are allowed to reproduce a small amount of someone’s work for the purposes of study, criticism or review. However, it is always necessary to acknowledge the creator of the work.
