Input Devices

1
Input Devices

• CS 4750
• September 21, 1999

2
Overview

• Characteristics, properties, and design rationale
  of input devices rather than a survey of input
  devices

3
Designing aninput device

• Input device must control 2 aspects of robotic
  dragonfly
• Provide for control of dragonfly in 3 dimensions
• Provide control to snap picture with cameras in
  eyes
• Can use any currently available technology -
  moneys no object!

4
Design Reflection

• Design ideas
• How did you feel when designing the input device?
• What was easy, what was frustrating?
• How did you go about deciding on a design?

5
More Design Reflection

• Is your input design usable for other tasks?
• Did you take into account flying speed when
  maneuvering in 3D?
• Did you consider feedback when designing your
  input device?

6
Feedback

• Input devices need to provide appropriate
  feedback to users to guide them in their
  interactions with the system
• Cannot arbitrarily separate input from output in
  system - need to think holistically about system
• What are some examples of feedback in existing
  input devices?

7
Task, Context Specific

• Input devices are best when they are well matched
  to a specific task and context
• Mouse vs. pen and tablet
• Keyboard vs. Thads twiddler

8
Matching Users

• Input devices should match psychological and
  physiological characteristics of intended users
• For example, Stephen Hawkings input system
  specifically addresses his physiological needs

9
Safe, Efficient, Enjoyable

• Whens the last time you enjoyed using a
  keyboard?

10
Input Device Characteristics (Summary)

• Should deliver feedback to user to guide,
  reassure, inform, and if necessary, correct
  users errors (textbook)
• Are most effective when they are task, context
  specific
• Should match physiological and psychological
  characteristics of users
• Should be safe, effective, efficient, and
  enjoyable

11
Defining an Input Device

• Given characteristics, how can we define what an
  input device is and what it does?

12
Defining an Input Device

• A device that, together with appropriate
  software, transforms information from the user
  into data that a computer application can
  process. (textbook, italics added)
• Transformation is key and carries a lot of
  baggage with it.
• Why is transformation so important?

13
Transformation of Information

• Communication of information always introduces
  signal noise
• Telephone game, translations between languages
  are good examples
• When transforming intentions to a form the
  computer can understand, we are changing the
  nature of the information and introducing noise

14
Transformation of Information

• Transformation introduces errors several ways
• Input devices can only accept information in very
  specific ways. This limits expressivity
• Input devices can only accept data in discrete
  packets and cannot perfectly represent full range
  of data from the real-world

15
Future Directions

• More freeform types of input
• Speech, handwriting recognition
• Allowing for more ambiguous forms of input
• Putting more smarts into the computer to guess
  what were trying to communicate
• Jen Mankoffs work in CRB good example of this