Input Design Lecture 11 1 BTEC HNC Systems Support Castle College 2007/8

Lecture Objectives We will consider what an interface is Understand the importance of user centred design Explore how designers can make it easier for the user We will consider input and data entry methods Research Validation Types Create input User Interface 2 BTEC HNC Systems Support Castle College 2007/8

User Interface Is the communication boundary between two entities –piece of software, a hardware device or a user. Our focus: the User Interface, i.e. the interface between a human and a computer. The user interface refers to: –the graphical, textual and auditory information the program presents to the user –the controls the user employs in order to control the program and manipulate data i.e. buttons, keystrokes from the keyboard, movements of the mouse (and mouse clicks) etc. Enables the computer and the user to communicate to each other (two way communication)

IBM and Microsoft devote a great deal of effort to make interfaces simple and easy to understand 4 BTEC HNC Systems Support Castle College 2007/8

Cognetics Corp. believe that an interface must be effective, efficient, engaging, error tolerant and easy to learn 5 BTEC HNC Systems Support Castle College 2007/8

Compare the two alternatives below Only one control box has an obvious meaning This message is hard to understand This message is much more detailed and useful to the user 6

User Centred Approach A good user interface design depends upon eight principles: Understand the basic underlying business function Maximise graphical effectiveness (people learn visually) Profile the system users 7

User Centred design Continued Think like a user (see system through users’ eyes) Use prototyping – construct models for approval Design a comprehensive interface (with all tasks, commands and communications needed) 8

User Centred design Continued Continue the feedback process (monitor usage and user suggestions) Document the interface design (for use by programmers) Follow guidelines for Interface Design 9

Make it easy for the users In order to create a successful interface we must ensure the following has been achieved: The user can easily obtain help Avoid errors (error checking) 10

Obtaining help – Guidelines: Ensure that help is always available (screens should provide information about menu choices, procedures etc) Provide User selected help (displays information when requested), and context sensitive help (offers assistance for the task in progress) Provide a direct route for users to return to the point where Help was requested (title every help screen and keep text simple and concise) 11

Obtaining help – Guidelines (cont.): Include contact information (if a Department or Help desk is responsible for assisting users) – must be easily maintainable Provide an Undo key or menu choice which allows the user to ‘undo’ the latest action. Request user confirmation before deleting data (are you sure?) Build in safeguards to ensure critical data is not lost. Use hyperlinks to help users navigate through Help topics 12

User selected help facility Context sensitive help 13

Avoiding Errors There are many ways to minimising data entry errors, some of which is outlined below: Provide data validation checks Display event driven messages and reminders Establish a list of pre-defined values that users can click to select Build in rules that ensure data integrity (e.g. new customer must be added before system will accept order) INPUT MASKS (which are templates or patterns that make it easier for users to enter data i.e. postcodes, dates etc) –Can be created in MS Access 14

Validation Checks Research Activity: Bring an example of each of these: 1.Sequence check 2.Existence check 3.Data type 4.Range check 5.Reasonableness 6.Validity checks 7.Combination checks 8.Batch controls, hash totals 15

Avoiding errors Reducing the number of input errors improves data quality Data validation checks test the data and reject any data that does not meet specified conditions The Quality of output is only as good as the quality of input - GIGO (garbage in garbage out) 16

Input and data entry methods Batch input (a large amount of data usually entered at the same time, e.g. sales transactions at the end of the day) Online Input (used for most business activity – has many advantages like immediate validation and availability of data) Source Data validation (uses input devices like magnetic data strips or hand held scanners) EPOS, ATM’s and related systems 17

Trade off - issues Manual data input is slower and more expensive than automated Often done when computer is at its busiest It is performed at the time the transaction occurs Automated and batch processing cheaper but depends on business process 18

Conclusion We have discussed about what an interface is We have learned about good user centred design for data input We have established how the design of the interface can make it easier for the users We have considered input methods, batch processing and tradeoffs 19