Term 2, 2011 Week 5

CONTENTS Data and information Information purposes Types of data – Integer data types – Floating point numbers – Character data types – String data types Questions

Information Technology focuses on the transformation of data into information, as well the management of that information. Understanding how data can be input, manipulated and output to create meaningful information is critical to being able to utilise various ICT tools to solve information problems.

Data can be defined as unprocessed, unorganised & distinct facts or ideas. In addition to text & numbers, data also includes sounds, images & video. A computer processes data into information. Information can be defined as processed or organised data. Input Manipulation/ Processing Output Storage

Information can take a number of forms. It can be: – Paper based (hard copy) Magazines Word-processed reports Newspapers – Digital (soft copy) – Action

Digital (or electronic) information can be used to present the same information as paper-based solutions, however the output is not designed to be printed. While digital information is often formatted so that it is best viewed on a screen, often websites will offer printer friendly pages, just in case their users wish to have a hard copy. Information can also take the form of some kind of action performed as the result of manipulation. Examples include: – Wii – where the Wii Remote takes in movement data, processes the data & allows the user to interact with & control items on a screen.

Often, organisations & individuals require information to support their decision making and problem solving needs. We can express these needs in terms of needing to inform, persuade, educate or entertain. We INFORM our audience when we are providing information or telling facts, such as reporting a current issue. We PERSUADE our audience when we influence a decision or action, or change a person’s opinion.

We ENTERTAIN when we engage in a activity in a pleasing or amusing way. We EDUCATE when we teach & provide knowledge and skills through a learning process.

A data type is a set of data with predefined characteristics. When we develop purpose-designed solutions, we will often be working with a number of different data types at the same time. This data can be entered, stored, manipulated or output.

For example – Entering student names or products on sale Numbers may need to be entered & these can be either whole numbers or decimals, as well as dates & Boolean (true/false) information. Data may also need to be stored permanently as a constant value in the solution.

Integer data types In IT, integers are a finite subset of numbers without any fractional or decimal component and can be positive or negative. There are several different formats for representing integer data & is dependant on the size of the numbers to be stored.

Floating point numbers Floating point numbers are those that are too small or too big to be stored as integers. FPN’s are stored in two parts: – The mantissa holds all of the digits with a decimal point after the first digit. – The exponent holds the power of 10 by which the mantissa must be multiplied to regain the original number.

Precision refers to the number of digits that can be stored. TypeRangePrecision Single1.5 x to 3.4 x Double5.0 x to 1.7 x Extended3.6 x to 1.1 x

Character data types Includes alphanumerical text such as letters, numbers, spaces, symbols & punctuation. Usually takes up 1 byte of space per character. Used in character fields that are not used in mathematical calculations.

String data types A string is a series of symbols or values, such as a character string. The maximum string length is generally 255 characters. Strings can be operated or manipulated, either as characters, whole words or as sentences.

Questions What are some advantages & disadvantages of printed & online newspapers? What are the four main purposes of information? Find an example of a website for each purpose. Suggest two publications (one paper-based and one digital) that you would use to promote a game-making business. How would this reach an audience and why would it be convincing? List the four types of data types and briefly explain what they are. Find five data sets using a search engine. List the URL and identify what data types they involve.