- Slides: 23
System Analysis and Design Input / Output Forms And User Interface Design
Input (Form) Design Objectives § § § Input Design is the process of converting user originated inputs to a computer based format. Main objectives include: Making completion easy and efficient Assuring input meets the intended purpose Assuring accurate completion Making screens and forms attractive Making input uncomplicated Creating screens and forms that are consistent
Output (Report) Design Objectives § § § Designing reports to serve a specific purpose Making reports meaningful to users Delivering the appropriate quantity of reports Providing appropriate output distribution Providing output on time Choosing the most effective output method
Designing Forms and Reports § Form and Report design are performed in the logical design phase. § Forms and Reports are integrally related to DFD and E-R diagrams.
Form and Report Overview ØForm § A business document that contains some predefined data and may include some areas where additional data are to be filled in § An instance of a form is typically based on one database record ØReport § A business document that contains only predefined data § A passive document for reading or viewing data § Typically contains data from many database records or transactions
Form/Report and DFD Relationship Ø Data input indicates forms while data output indicates reports. Ø Thus, prototypes are needed for designing forms and reports.
Forms and Reports Designing Process Collect and analyze data needed Ø Determine requirements Ø Who will use the form or report? What is the purpose of the form or report? When is the report needed or used? Where does the form or report need to be delivered and used? ◦ How many people need to use or view the form or report? ◦ ◦ Outline possible forms and reports Ø Follows a prototyping approach Ø
Forms and Reports Designing Process § Prototyping § Initial prototype is designed from requirements § Users review prototype design and either accept the design or request changes § If changes are requested, the construction-evaluation -refinement cycle is repeated until the design is accepted
General Guidelines for Forms and Reports Information Categories in Source Document ØInternal Information ØExternal Information ØHybrid Information Ø Information Mediums ØSoft Copy (On Screen) ØHard Copy(Paper) Ø Rules in Designing Forms and Reports ØClear Titles ØContain needed information ØEffective alignment and balanced structure ØEasy to use Ø
User Interface Design User interface design is designing effective interfaces for software systems. Objectives ◦ To suggest some general design principles for user interface design ◦ To explain different interaction styles ◦ To introduce styles of information presentation ◦ To introduce usability attributes and system approaches to system evaluation
Need for User Interface Design System users often judge a system by its interface rather than its functionality A poorly designed interface can cause a user to make illogical errors Poor user interface design is the reason why so many software systems are never used Most users of business systems interact with these systems through Graphical User Interfaces (GUIs) In some cases, legacy text-based interfaces are still used(CUIs)
GUI advantages They are easy to learn and use. ◦ Users without experience can learn to use the system quickly. The user may switch quickly from one task to another and can interact with several different applications. ◦ Information remains visible in its own window when attention is switched. Fast, full-screen interaction is possible with immediate access to anywhere on the screen
User Interface Design Process
UI design Principles User familiarity ◦ The interface should be based on user-oriented terms and concepts rather than computer concepts ◦ E. g. , an office system should use concepts such as letters, documents, folders etc. rather than directories, file identifiers, etc. Consistency ◦ The system should display an appropriate level of consistency ◦ Commands and menus should have the same format, command punctuation should be similar, etc.
UI Design Principles (cont. ) Minimal surprise ◦ If a command operates in a known way, the user should be able to predict the operation of comparable commands Recoverability ◦ The system should provide some resilience to user errors and allow the user to recover from errors ◦ This might include an undo facility, confirmation of destructive actions, 'soft' deletes, etc.
UI Design Principles (cont. ) User guidance ◦ Some user guidance such as help systems, on-line manuals, etc. should be supplied User diversity ◦ Interaction facilities for different types of user should be supported ◦ E. g. , some users have seeing difficulties and so larger text should be available
UI Design Principles (cont. ) Aesthetically Pleasing ◦ Provide visual appeal by: Providing meaningful contrast between screen elements Creating groupings Aligning screen elements and groups Providing three-dimensional representation Using colour and graphics effectively and simply
UI Design Principles (cont. ) Clarity ◦ The interface should be visually, conceptually, and linguistically clear, including: Visual elements Functions Words and text Compatibility ◦ Provide compatibility with the following: The user The task and job The product ◦ Adopt the user’s perspective
UI Design Principles (cont. ) Directness ◦ Provide direct ways to accomplish tasks. Available alternatives should be visible. The effect of actions on objects should be visible. Efficiency ◦ Minimize eye and hand movements, and other control actions. Transitions between various system controls should flow easily and freely. Navigation paths should be as short as possible. Eye movement through a screen should be obvious and sequential. ◦ Anticipate the user’s wants and needs whenever possible.
UI Design Principles (cont. ) Familiarity ◦ Employ familiar concepts and use a language that is familiar to the user Keep the interface natural, mimicking the user’s behaviour patterns Use real-world metaphors Flexibility ◦ A system must be sensitive to the differing needs of its users, enabling a level and type of performance based upon: Each user’s knowledge and skills Each user’s experience Each user’s personal preference Each user’s habits ◦ The conditions at that moment
UI Design Principles (cont. ) Responsiveness ◦ The system must rapidly respond to the user’s requests. ◦ Provide immediate acknowledgment for all actions: Visual Textual Auditory Safety ◦ Protect the user from making mistakes. ◦ Provide visual cues Reminders Lists of choices Other aids as necessary
UI Design Principles (cont. ) Transparency ◦ Permit the user to focus on the task or job, without concern for the mechanics of the interface. Workings and reminders of workings inside the computer should be invisible to the user Trade-Offs ◦ Final design will be based on a series of trade-offs balancing often-conflicting design principles. ◦ People’s requirements always take precedence over technical requirements.