input design 1. input design comes after the design of outputs. output design comes first as a...
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INPUT DESIGN
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•Input design comes after the design of outputs. Output design comes first as a system validation test.•Input design concepts and guidelines are based on ‘Garbage in, garbage out’ (GIGO)•The quality of system input determines the quality of system output.
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Input DesignDefine the appropriate format and
media for a computer input.
Explain the difference between data
capture, data entry, and data input.
Identify and describe several
automatic data collection technologies.
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Apply human factors to the design of
computer inputs.
Design internal controls for computer inputs.
Select proper screen-based controls for
input attributes that are to appear on a GUI
input screen.
Design a web-based input interface.
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Data Capture and Data EntryData capture – the identification and
acquisition of new data (at its source).
Source documents – forms used
to record business transactions in
terms of data that describe those
transactions.
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Data entry – the process of
translating the source data or
document (above) into a computer
readable format.Data processing – is all processing
that occurs on the data after it is input from a machine readable form.
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In batch processing, the entered data is collected into files called batches and processed as a complete batch.
In on-line processing, the captured data is processed immediately
In remote batch processing, data is entered and edited on-line, but collected into batches for subsequent processing.
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Input Implementation Methods
KeyboardMouseTouch ScreenPoint-of-sale terminalsSound and speechAutomatic data capture
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Optical mark recognition (OMR)
Bar codes
Optical character recognition (OCR)
Magnetic Ink
Electromagnetic transmission
Smart cards
Biometric 9
Taxonomy for Computer Inputs Process Method
Data Capture Data Entry Data Processing
Keyboard
Data is usually captured on a business form that becomes the source document for input. Data can be collected real-time.
Data is entered via keyboard. This is the most common input method but also the most prone to errors.
OLD: Data can be collected into batch files (disk) for processing as a batch.NEW: Data is processed as soon as it has been keyed.
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Taxonomy for Computer Inputs
Mouse Same as above
Used in conjunction with keyboard to simplify data entry. Mouse serves as a pointing device for a screen.
Same as above, but the use of a mouse is most commonly associated with online and real-time processing.
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Taxonomy for Computer Inputs Touch Screen
Same as above.
Data is entered on a touch screen display or handheld device. Data entry users either touch commands and data choices or enter data using handwriting recognition.
On PCs, touch screen choices are processed same as above. On handheld computers, data is sorted on the handheld for later processing as a remote batch.
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Taxonomy for Computer Inputs
Point of Sale
Data is captured as close to the point of sale as humanly possible. No source documents.
Data is often entered directly by the customer or by an employee directly interacting with the customer.
Data is almost always processed immediately as a transaction or inquiry.
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Taxonomy for Computer InputsProcess Method
Data Capture Data Entry Data Processing
Sound Data is captured as close to the source as possible, even when the customer is remotely located.
Data is entered using touch-tones (typically from a telephone). Usually requires fairly rigid command menu structure and limited input options.
Data is almost always processed immediately as a transaction or inquiry.
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Speech Same as sound
Data (and commands) is spoken. This technology is not as mature and is much less reliable and common than other techniques.
Data is almost always processed immediately as a transaction or inquiry.
Taxonomy for Computer Inputs
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Optical Mark
Data is recorded on optical scan sheets as marks or precisely formed letter, numbers, and punctuation.
Eliminates the need for data entry.
Data is almost always processed as a batch.
Taxonomy for Computer Inputs
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Magnetic Ink
Data is usually prerecorded on forms that are subsequently completed by the customer. The customer records additional information on the form.
A magnetic ink reader reads the magnetized data. The customer-added data must be entered using another input method.
Data is almost always processed as a batch.
Taxonomy for Computer Inputs
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Process Method
Data Capture
Data Entry Data Processing
Electromagnetic
Data is recorded directly on the object to be described by data.
Data is transmitted by radio frequency.
Data is almost always processed immediately.
Taxonomy for Computer Inputs
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Automatic Identification: Bar Codes
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Input Design GuidelinesCapture only variable data.
Not data that can be looked up.Do not capture data that can be
calculated or stored in computer programs as constants.Extended Price, Tax Withholding,
etc.Use codes for appropriate attributes.20
Source Document / Form Design Guidelines
Include instructions for completing the form.
Minimize the amount of handwriting.Data to be entered (keyed) should be
sequenced top-to-bottom and left-to-right.When possible use designs based on
known metaphors.
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Good Flow in a Form
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Bad Flow in a Form
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Metaphoric Screen Design
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Internal Controls for InputsThe number of inputs should be
known (to minimize risk of lost transactions).For batch processing
Use batch control slipsUse one-for-one checks against
post-processing detail reports
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For on-line systems Log each transaction as it occurs to a separate
audit fileValidate all data Existence checks Data-type checks Domain checks Combination checks Self-checking digits Format checks
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Common GUI Controls (Windows and Web)
Text boxesRadio buttonsCheck boxesList boxesDrop down
listsCombination
boxesSpin boxesButtons
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Common GUI Controls UsesText boxes
When the input data values are
unlimited in scope
Radio buttons
When data has limited
predefined set of mutually
exclusive values28
Check boxes
When value set consists of a
simple yes or no value
List boxes
When data has a large number
of possible values
Common GUI Controls Uses
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Drop down lists
When data has large number of possible values
and screen space is too limited for a list box
Combination boxes
When need to provide the user with option of
selecting a value from a list or typing a value
that may or may not appear in the list
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Spin boxesWhen need to navigate through
a small set of choices or directly
typing a data value
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Advanced Controls (mostly Windows interfaces)
Drop down calendars
Slider edit controlsMasked edit
controlsEllipsis controlsAlternate
numerical spinnersCheck list boxesCheck tree boxes
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Advanced Controls (mostly Windows interfaces)
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Automated Tools for Input Design and Prototyping
Old ToolsRecord Layout ChartsDisplay Layout Charts
Newer Prototyping ToolsMicrosoft Access, CASE Tools,
Visual Basic, Excel, Visio
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Input Design Process
1. Identify system inputs and review
logical requirements.
2. Select appropriate GUI controls.
3. Design, validate and test inputs
using some combination of:
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a)Layout tools (e.g., hand sketches,
spacing charts, or CASE tools.
b)Prototyping tools (e.g.,
spreadsheet, PC DBMS, 4GL)
4. As necessary design source
documents.
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Design Process Cont….Develop prototype screens for users to review Develop prototype screens for users to review
and test. Their feedback may result in the and test. Their feedback may result in the need to add new attributes and address their need to add new attributes and address their characteristicscharacteristics
To prototype input screens, the designer needs To prototype input screens, the designer needs to let the user exercise or test the screens and to let the user exercise or test the screens and this may involve demonstrating how the user this may involve demonstrating how the user may obtain appropriate help or instructions. may obtain appropriate help or instructions.
Prototypes need not display all the details to a Prototypes need not display all the details to a user unless they are requesteduser unless they are requested
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A Logical Data Structure for Input Requirements
ORDER = ORDER NUMBER+ ORDER DATE+ CUSTOMER NUMBER+ CUSTOMER NAME+ CUSTOMER SHIPPING
ADDRESS = ADDRESS >+ ( CUSTOMER BILLING
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ADDRESS = ADDRESS >)+ 1 {PRODUCT NUMBER + QUANTITY ORDERED } n+ ( DEFAULT CREDIT CARD NUMBER )
ADDRESS = (POST OFFICE BOX NUMBER)+ STREET ADDRESS+ CITY+ STATE+ POSTAL ZONE
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Input Prototype for Video Title Maintenance
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Input Prototype for Member Order
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Input Prototype for Member Shopping
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Input Prototype for Web Shopping Cart
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Input Prototype for Web Interface
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USER INTERFACE
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User interface Technology
Types of User Interfaces
Guidelines for dialog Design
Feedback for users
Designing Queries
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System User Classifications
An expert user is an experienced computer user who will spend considerable time using specific application programs. The use of a computer is usually considered non-discretionary. In the mainframe computing era, this was called a dedicated user.
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System User Classifications…
The novice user (sometimes called a casual user) is a less experienced computer user who will generally use a computer on a less frequent, or even occasional, basis. The use of a computer may be viewed as discretionary (although this is becoming less and less true)
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Designing effective interfacesSystem users often judge a system by its
interface rather than its functionalityPoor user interface design is the reason why
so many software systems are never usedA poorly designed interface can cause a user
to make catastrophic errorsMost users of business systems interact
through graphical interfaces
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User interface design process
Executableprototype
Designprototype
Produce paper-based design
prototype
Producedynamic design
prototype
Evaluate designwith end-users
Implementfinal userinterface
Evaluate designwith end-users
Analyse andunderstand user
activities
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Commandments of User Interface Design
Understand your users and their tasks.
Involve the user in interface design.
Test the system on actual users.
Practice iterative design.
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Objectives to Address Matching the user interface to the task Making the user interface efficient Providing appropriate feedback to
users Generating useable queries Improving productivity of
knowledgeable workers
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A: Types of user interfaces:- Natural Language interfaces Question and answer interfaces Menus Form-fill interfaces (Input/Output forms Command Language interfaces Graphical User interfaces Other user interfaces
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Form-based interface example
Title
Author
Publisher
Edition
Classification
Date ofpurchase
ISBN
Price
Publicationdate
Number ofcopies
Loanstatus
Orderstatus
NEW BOOK
Iconic Menus
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Command interfaces disadvantages
oCommands of arbitrary complexity
can be created by command
combination
oUsers have to learn and remember
a command language – unsuitable
for occasional users
Command interfaces disadvantages….
oUsers make errors in command.
An error detection and recovery
system is required
oSystem interaction is through a
keyboard so typing ability is
required
B: Guidelines For Dialogue Meaningful communication
Title for each display
Minimum use of abbreviations
Clear user feedback
Warning signs when the user enters the wrong information
Help menuClearly identifying key data such as date by
slashes etc.
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User-system interaction
Two problems must be addressed in
interactive systems design
How should information from the
user be provided to the computer
system?
How should information from the computer
system be presented to the user?
User interaction and information
presentation may be integrated through a
coherent framework such as a user interface
metaphor
Minimal User Interaction
Keying codes of whole words
Supplying the edited characters
i.e. slashes in a date or the KSH
after a monetary amount has
been entered.
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Using default values e.g. when typing
the year January the system
highlights the full word and you just
have to press enter
Remembering last entered
information e.g. passwords, birthdays,
names of users etc
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Use of an inquiry program so
that the user only has to enter the
first few characters
Providing key strokes e.g. to
copy just press “Ctrl + C”
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Standard Operation and Efficiency
Exiting each program using the
same keys
Locating titles, dates, time etc at the
same places on all displays
Obtaining help in a standardized way
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Standardizing the colors used in
all displays
Standardizing the use of icons
Consistent terminology in a
display screen or web site
Using consistent fonts, sizes,
colors etc65
Guidelines for Dialogue- 3 : Example of use of consistency in fonts
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Feedback for users
Compares current behaviors with the
goals set out by the user of
programmer
Satisfy the psychological needs of
humans and as well as to provide
confidence to the user67
The computer has accepted the
input. E.g by advancing cursor to
the next letter to be typed in
The input is in the correct form.
The computer simply says “Ready”
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The input is not in the correct form
There will be a delay in the processing
The request has been completed
The computer is unable to complete the request
More detailed feedback is available (and how to get it)
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Feedback- Wrong data entered
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Human Engineering Guidelines
The screen should be formatted
so that the various types of
information, instructions, and
messages always appear in the
same general display area.
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Messages, instructions, or information
should be displayed long enough to
allow the system user to read them.
Default values for fields and answers
to be entered by the user should be
specified.
Anticipate the errors users might make.
With respect to errors, a user should not be
allowed to proceed without correcting an error.
If the user does something that could be
catastrophic, the keyboard should be locked to
prevent any further input, and an instruction to
call the analyst or technical support should be
displayed.
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DESIGN & PROTOTYPE OF USER INTERFACE
User Interface (UI) is the system of computer screen images, devices, and software components that allow the user to interact with and control a computer system. Graphical user interfaces (GUI) allow the user to interact with the software system by manipulating icons or menus. 74
DESIGN OF UI
User interface design in the context
of creating software represents an
approach that puts the user, rather
than the system, at the center of the
process.
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This philosophy, called user-centered
design, incorporates user concerns
and advocacy from the beginning of
the design process and dictates that
the needs of the user should be
foremost in any design decisions
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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.
GUI Advantages…..
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
GUI DESIGN PRINCIPLESDevice consideration
Visibility of system status
Match between system and the real world
User control and freedom
Consistency and standards
Error prevention 79
Recognition rather than recall
Flexibility and efficiency of use
Aesthetic and minimalist design
Help users recognize, diagnose, and
recover from errors
Help and documentation
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Device consideration
Consider the end-user device, where the system shall be installed finally. Is the device a PC, Mobile device e.g. Pocket PC or mobile phone. User interface of Pocket PC is usually very compact and does not require much information, while the PC has got a lot of redundant space. Do not overload the Pocket PC interface with controls
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GUI PROTOTYPEThe beside UI prototype shows the simplicity and device consideration in GUI design. The application is designed for Pocket PC, which has very limited space. There are very few controls done in symbols and short hand considering the compactness of a Pocket PC
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Visibility of system status
The system should always keep users informed about what is going on, through
appropriate feedback
within reasonable time. 83
Match between system and the real world
The system should speak the users' language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.
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User control and freedom
Users often choose system functions by mistake and will need a clearly marked "emergency exit" to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.
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Consistency and standards
Users should not have to wonder
whether different words, situations, or
actions mean the same thing. Follow
platform conventions.
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The beside GUI Menus considers consistency with Microsoft Windows (see File, Edit etc.). The interface is consistent with most standard systems. The use of Metaphoric icons to denote actions and events is also visible
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Error prevention
Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.
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Recognition rather than recall
Minimize the user's memory load by
making objects, actions, and options
visible. The user should not have to
remember information from one part
of the dialogue to another.
Instructions for use of the system
should be visible or easily retrievable
whenever appropriate. 89
Flexibility and efficiency of use
Accelerators – unseen by the novice user – may often speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.
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Aesthetic and minimalist design
Dialogues should not contain
information which is irrelevant or
rarely needed. Every extra unit of
information in a dialogue competes
with the relevant units of information
and diminishes their relative visibility91
Help users recognize, diagnose, and recover from errors
Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.
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Help and documentation
Even though it is better if the system
can be used without documentation, it
may be necessary to provide help and
documentation. Any such information
should be easy to search, focused on
the user's task, list concrete steps to
be carried out, and not be too large. 93
Help System Design
Help? means ‘help I want information”
Help! means “HELP. I'm in trouble”
Both of these requirements have to be
taken into account in help system design
Different facilities in the help system
may be required
Help System Design….
Should not simply be an on-line
manual
The dynamic characteristics of
the display can improve
information presentation
User DocumentationAs well as on-line information, paper
documentation should be supplied with a system
Documentation should be designed for a range of users from inexperienced to experienced
As well as manuals, other easy-to-use documentation such as a quick reference card may be provided
Error messages
Error message design is critically important. Poor error messages can mean that a user rejects rather than accepts a system
Messages should be polite, concise, consistent and constructive
The background and experience of users should be the determining factor in message design
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Nurse input of a patient’s name
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Design factors in message wording
Context The user guidance system should be aware of what the user isdoing and should adjust the output message to the currentcontext.
Experience As users become familiar with a system they become irritatedby long, ‘meaningful’ messages. However, beginners find itdifficult to understand short terse statements of the problem.The user guidance system should provide both types of messageand allow the user to control message conciseness.
Skill level Messages should be tailored to the user’s skills as well as theirexperience. Messages for the different classes of user may beexpressed in different ways depending on the terminology whichis familiar to the reader.
Style Messages should be positive rather than negative. They shoulduse the active rather than the passive mode of address. Theyshould never be insulting or try to be funny.
Culture Wherever possible, the designer of messages should be familiarwith the culture of the country where the system is sold. Thereare distinct cultural differences between Europe, Asia andAmerica. A suitable message for one culture might beunacceptable in another. 99
Interface Problems
According to Galitz, the following
problems result in confusion, panic,
frustration, boredom, misuse,
abandonment, and other undesirable
consequences
Excessive use of computer
jargon and acronyms
Interface Problems….
No obvious or less-than-intuitive design
Inability to distinguish between alternative
actions (“what do I do next?”)
Inconsistent problem solving approaches
Design inconsistency
User Interface Evaluation
Attribute DescriptionLearnability How long does it take a new user to
become productive with the system?Speed of operation How well does the system response match
the user’s work practice?Robustness How tolerant is the system of user error?Recoverability How good is the system at recovering from
user errors?Adaptability How closely is the system tied to a single
model of work?
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Thank You
END103