Presentation on theme: "Human Computer Interface"— Presentation transcript:
1 Human Computer Interface A term used to describe the interaction between the user and a computer. The method by which the user tells the computer what to do and the responses which the computer makes
2 Importance of good interface design A good interface design ensures that users carry out their tasksSafely – think of a pilot flying a jumbo jetEffectively – operating a video recorder successfully to record the correct programEfficiently – users can obtain money from a cash machine, inserting card and pin, obtaining cash and removing their cardEnjoyably – can use a computer program to learn tables, for example
3 Interface Styles There are a number of interface styles including: Command line interfaceMenusNatural LanguageForms and dialogue boxesWIMP
4 Command Line Interface Provides a means of expressing instructions to the computer directly using single characters, whole word commands or abbreviations.Very little help is given.Commands enable a user to quickly and concisely instruct the computer what to doUser requires the knowledge of the commands available and the syntax for using themOperates via DOS
5 Menu interfaceFull screen menu – front end application use. Stays on screen until the user makes a choice. Eg A switchboard on a databasePull down menu – displayed along the top of a screen. When the user clicks on an item, a submenu appears. Always present at the top of the screen whatever screen the user is looking at in the application.Pop-up menu – menu pops up due to a response, say, a click of the right mouse button on a particular area of the screen.
6 Natural Language – “plain English” AdvantagesNo need for training in a specialised command languageExtremely flexible and powerfulUser is free to construct her own commands, frame her own questions, etc.DisadvantagesPeople find it difficult to stick to grammatical correct EnglishA well designed artificial language can say the same thing more concisely than natural languageA natural language can mislead a user into believing the computer is more intelligent than it actually is
7 Forms & Dialogue BoxesA form is used to enter data, such as customers names.A dialogue box is a special type of form, usually in the Windows environment, for example, a form appears when a print job is set up to the printer.Points to consider when designing a form:-Should have a title to identify itNot be too cluttered – space and blanks are importantCorrections should be allowed before the data is acceptedItems should appear in a logical sequence to assist the userDefault values should be set up whenever possible so a minimum of data entry is requiredFull help and exit facilities should be provided
8 WIMP Interface Windows, Icons, Mouse and pull down menus. Window – area on screen through which a particular piece of software or data file may be viewed.The window can be the whole screen or several windows can be set up, each one being moved or resized, as necessary.An icon is a small picture representing an item such as a piece of software. Selected by using the mouse.Mouse moves a cursor, positioning it were required and then selecting the item.