the nature of data and information 11 ipt miss o’grady

The Nature of The Nature of Data and Data and

InformationInformation

11 IPT11 IPT

Miss O’GradyMiss O’Grady

Data Data Information Information

Data = Raw material entered into an information

system.

7 Information Processes: Operate on the inputted

data to transform it into information.

The information coming out of one information

system can then be used as data going into further

information systems.

Data Data Information InformationThe distinction between data and information is

important. Example: An organisation may perform

thousands of transactions each day, and record

them using an information system. Simply making

a printout of every transaction however, will not

provide useful information for managers.


The information processes of organising,

analysing, processing and displaying help to

convert data into information using methods

such as:• Choosing data pertinent to the problem• Deleting irrelevant data• Combining data• Displaying data in an understandable way


The data, and information used by an

information system is of various types, each

suited to different tasks.

Different Types of Different Types of MediaMedia

Media refers to something in the middle that is

used to transmit a message of some sort. This is

what the press does, it transmits news, a form of

information, using TV, radio or print media.

The term ‘multimedia’ is used to refer to

information that combines text, sound, graphics

and/or video.


Different types of media commonly used by information systems, namely:

Text

Numbers

Image

Audio

Video

These provide a method for representing data and

communicating information.


Each media type conveys different information and it is used to represent different types of data, yet computers represent all types of media in binary.

BinaryBinaryWhat is Binary?

‘Binary is a number system, just like the familiar decimal system, except rather than ten digits it uses only two, names 0 and 1’.

Computers ultimately represent all the different types of media as a sequence of 0s and 1s. It is the way this data is organised that makes it meaningful and therefore able to be transformed into information.

Complete ‘Group Task- Complete ‘Group Task- Discussion pg.54’.Discussion pg.54’.

TextTextThe text media type is used to represent characters. These characters can be printable, such as letters of the alphabet, or non-printable, such as returns/enter or tabs.

What makes data a candidate for the text media type?Any data that is composed of a string of distinct characters where the order of the characters is important but each character, when considered in isolation, has a constant meaning regardless of this order.

ASCIIASCIIHandout- ‘The ASCII Table’

Example: The text ‘The cat sat on the mat’ would be likewise represented as 84 104 101 32 99 97 116 32 111 32 116 104 101 32 109 97 116 46

Read pg.56 of textbook. Explanation. Complete ‘Group Task- Activity’ pg. 56

Binary Code

128128 6464 3232 1616 88 44 22 11

00 11 00 00 11 00 00 11

64 + 8 + 1 = 7364 + 8 + 1 = 73

ASCII for 73 = IASCII for 73 = I

NumbersNumbersThe number media type is used to represent integers (whole numbers), real numbers (decimal numbers), currency and even dates and times.

Homework: Homework:

Read and take notes on Read and take notes on

the individual numbers pg.57-58.the individual numbers pg.57-58.

ImagesImagesThe image media type is used to represent data that

will be displayed as visual information. Using the

definition all information displayed on monitors and

printed as hardcopy is represented as images. This is

true, all monitors and printers are used to display

image media, however text and numbers are organised

into image data only in preparation for display.

ImagesImages

There are essentially two different techniques for

representing images; bitmap or vector.

BitmapBitmapBitmap images represent each element or dot in the picture

separately. These dots are called pixels (short for picture element)

and each pixel can be a different colour and is represented as a

binary number.

The number of colours present in an image has a large impact on

the overall size of the binary representation.

Example: A black and white image requires only a single bit for

each pixel, 1 meaning black and 0 meaning white. For 256 colours,

8 bits are required for each pixel so the image would require 8

times the storage of a similarly sized black and white bitmap

image.

BitmapBitmap

The resolution is the number of pixels the image contains and is

usually expressed in terms of width by height.

The image of the paintbrush has been enlarged having each pixel merely made larger. When using

bitmap images it is vital to consider the likely display device to be used

to determine the resolution required.

VectorVector

Vector images represent each portion of the image mathematically. That is, the data used to generate the image is a mathematical description of each shape that makes up the final image. Each shape within a vector image is a separate object that can be altered without affecting other objects. Example: A single line within a vector image can be selected and its size, colour, position or any other property altered independent of the rest of the image.