13-1 © prentice hall, 2004 chapter 13: designing the human interface (adapted) object-oriented...

13-1 © Prentice Hall, 2004

Chapter 13:Chapter 13:Designing the Human Designing the Human

InterfaceInterface(Adapted)(Adapted)

Object-Oriented Systems Analysis and Design

Joey F. George, Dinesh Batra,

Joseph S. Valacich, Jeffrey A. Hoffer

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Chapter ObjectivesChapter Objectives

- Concept of User interface– Forms and reports– General guidelines for forms and reports– Dialogue design– Usability Testing; Web Usability

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Note: In OO Development, user interface is designedin cycles.

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• UI refers to all the screens through which User provides input to the system and gets output from the system.

• Forms and reports are types of UI supporting access to databases.

- Very common since databases part of almost any system.

- BUT, not only type of UI!!! (book’s bias)

Concept of User Interface (UI)Concept of User Interface (UI)

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FormForm

- Input and output object

- Input form object: A business document that contains some predefined data and may include some areas where additional data are to be filled in

- Typically based on a database record or query

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ReportReport

A business document that contains only predefined data

A passive document meant only for reading or viewing, not data input

Typically contains data from many unrelated transactions or records

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Visual Basic and other development tools provide computer-aided GUI form and report generation.

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A typical form design specification:

Based on a use case connection – Boundary Class

Involves three parts:

1) Narrative overview2) Sample design3) Assessment

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Grouping, organization, layout, and highlighting are important considerations in form design

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Highlighting can include use of upper case, font size differences, bold, italics, underline, boxing, and other approaches.

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Business reports are static, no user interaction. Therefore, business reports are often printed in hardcopy form.

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Bar and line graphs give pictorial summary information that can enhance reports and graphs.

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Dialogue DesignDialogue Design

– Layout (of widgets, text, and table data)– Structuring data entry (tab order)– Controlling data input (validation and format controls)– Systems’ Feedback (prompting, status, warning, and

error messages)– Dialogue sequencing

Dialogue - A sequence of interactions between the system and a user. Design includes:

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A typical interface/dialogue design specification:

Similar to form design, but includes multiple forms and dialogue sequence specifications

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Data entry structure is concerned with navigation flow.

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Navigation flow should be natural and intuitive to the user, not disjointed and confusing.

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Also a guideline for UI: Never make slidelike this – for number of lines use 7 +/- rule!

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System’s Feedback System’s Feedback

Status information – keep user informed of what’s going on, helpful when user has to wait for response

Prompting cues – tell user when input is needed, and how to provide the input

Warning or Error – informs user that something is wrong, either with data entry or system operation

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Guidelines for Dialogue DesignGuidelines for Dialogue Design

– Consistency

– Allow sequence, shortcuts, and reversals in navigation

– Frequent feedback

– Logical grouping and sequencing of diagrams, with beginning, middle, and end

– Comprehensive error handling

– Maximize ease and control of use

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Dialogue sequencing

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Dialogue diagrams depict the sequence, conditional branching, and repetition of dialogues.