DESIGN OF INPUT

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Input and Output Design
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DESIGN OF INPUT

• Design of input includes
• Selection of capture, entry and input method
• Selection of input method
• Selection of input device
• Selection of dialogue type
• Designing the user interface
• Design of data entry screens
• Designing data entry procedures
• Design of forms (paper)
• Coordination of screens
• (Design of training technique).

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The resulting design must be

• Easy to use
• Attractive
• Simple (uncluttered)
• Consistent (similar layout on forms/screens)
• Accurate (assures proper completion)
• Effective (gets only what is needed).

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• Data Capture, Data Entry, and Data Input
• Data capture is the identification of new data to
  be input.
• Data entry is the process of translating the
  source document into a machine-readable format.
  That format may be a magnetic disk, an
  optical-mark form, a magnetic tape, or a floppy
  diskette,
• Data input is the actual entry of data in a
  machine readable format into the computer.
• Data accompanies business events called
  transactions.
• Systems analysts must determine when and how to
  capture the data.
• It's always best to capture the data as soon as
  possible after it is originated.

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• Data Capture, Data Entry, and Data Input (cont)
• Traditionally, source documents were used to
  capture the data.
• A source document is a paper form used to record
  data that will eventually be input to a computer.
  
• With advances in video display technology, screen
  display forms are able to duplicate the
  appearance of paper based forms.
• Screen display forms and source documents must be
  designed to be easy for the system user to
  complete and should facilitate rapid data entry.
• Accuracy of data is affected by the design of
  data capture, entry and input techniques.

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• Common methods for data entry
• Batch input (data entry is delayed)
• On-Line input (data entry is immediate, but
  database updates may be delayed)
• Real-Time (database is immediately updated).
• Capture data as soon as possible.

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Selection of input device

• Possible choices include
• Keyboard Light pen
• Touch screen Mouse
• Mark sense Punch cards
• Bar codes Voice recognition
• Smart Cards Electromagnetic
• OCR (optical character recognition)
• MICR (magnetic ink character recognition)
• Select the method best suited for application

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• Consider the user, the application, the
  environment to determine the input device.
• Text based entry (or other type of information)
• User familiarity with device
• Required speed, accuracy
• Multi-lingual application
• Harsh environment
• Cost
• Closed or open responses
• Operator skill
• Quantity of data

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Designing Dialogue

• Dialogue is the style of interaction between the
  user and the interface.
• Menus
• Question and Answer
• Input/output forms
• Natural Language
• Command-Language
• Direct-Manipulation

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• To select an appropriate dialogue style consider
• The Application
• And
• The User
• What kind of users will the system have?
• Many one time users
• Untrained personnel
• Trained operators
• Frequent users
• Systems programmers.

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Characteristics of Users

• Many one time users
• Training impossible. Little understanding of the
  task.
• Untrained personnel
• Low panic threshold. Frequent problems will lead
  to system avoidance. Need very small and precise
  steps.
• Frequent users
• Need to complete task as quickly and easily as
  possible, but often start as an untrained user.
• Trained operators
• Are annoyed by tedious steps. Useful shortcuts
  required.
• Systems programmers
• Like to feel in control. They don't panic easily.

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Dialogue/Interface Types

• Menus
• Allow users to complete a task without knowing
  the entire system.
• Inexperienced users find them easy to use.
• Nesting and pull down menus are common
  techniques.
• Experienced users may not like stepping through
  multiple menus.

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Dialogue/Interface Types

• Question and Answer
• Computer supplies series of questions to which
  the user responds.
• Dialogue boxes are a common form.
• Questions can be tailored' as session continues.
• May be useful for one time users.
• Designer must consider the range of possible
  responses.

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Dialogue/Interface Types

• Input/output forms
• Common technique for data entry (form fill-in).
• Show what data is required.
• User can easily move between fields.
• Experienced users want defaults and/or shortened
  data entry techniques.

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Dialogue/Interface Types

• Natural Language
• Users enter a statement in natural language, the
  computer interprets it or asks for more
  information.
• Suits queries on databases or AI.
• Limited by the ambiguity of language.

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Dialogue/Interface Types

• Command-Language
• User controls dialogue and allowed high degree of
  control.
• Requires memorisation and complete understanding
  of task.

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Dialogue/Interface Types

• Direct-Manipulation
• Allows user direct manipulation of the screen.
• Text editors, spread sheets, video games.
• Graphical User Interface
• Requires sophisticated system.

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• Rules for Dialogue Design
• 1. Strive for consistency
• 2. Enable frequent users to use shortcuts
• 3. Offer informative feedback
• 4. Design dialogues to yield closure
• 5. Offer simple error handling
• 6. Permit easy reversal of actions
• 7. Support internal locus of control
• 8. Reduce short-term memory load.

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Designing the user interface

• Design of data entry screens
• Designing data entry procedures
• Coordination of screens
• Design of forms (paper)