YA Singlehanded Input Device - Mock-Up 3

Toke Eskildsen


It is assumed that the reader is familiar with idea behind Yashid and the principle for the text-entering.

This mock-up is about the usability of the device. It is possible to enter text on a Windows based computer using the physical artifact.


The physical artifact used in this mock-up resembles a cell-phone or a PDA, as described in Mock-Up 2. It connects to a PC running Windows 95/98/ME/NT40/2000 using the parallel-port. The artifact was constructed using an old Genius-mouse and some buttons from a broken radio. Technical facts abous connections and wiring are available.

[Assembly 1] [Assembly 2] [Final product] [Handling 1] [Handling 2]


[Screenshot 2001-05-08]

The software part of Yashid has reached version 0.3.4, adding support for typing using an artifact connected to a PC's parallel port. Due to restraints imposed by Windows NT and Windows 2000, the user has to install a driver for the parallel-port.

The software has been extended from previous versions with the capability of polling the parallel port for signals. The address for the parallel port is obtained by retrieving the system's address for the parallel port (LPT), converting it to decimal and adding 1.

Usability test 1

Areas of interest

First test

Since this is the first physical mock-up, it is to be expected that physical problems will occur. The viability of Yashid is closely connected to the artifact so it is necessary to get that aspect at least a bit right. Therefore the first test must include evaluation in the form of the physical use of the artifact.

  1. The user receives a very short introduction to the way Yashid works and are given one minute to experiment with the mock-up.
    Expectation: The user masters the principle behind Yashid in a very short time.
  2. The user is asked to type a specific text (see below) for 5 minutes
    Expectation: The typerate will be very low.
  3. The user is asked to describe good or bad things about the physical aspect of the artifact.
    Expectation: Lots of room for improvement, the buttons are too hard, the shape is awkward.
  4. The user is asked to type for another 5 minutes.
  5. Expectation: The typerate is a lot better than the first 5 minutes.
  6. The user is asked for more feedback om the physical use of the artifact, with particular appention to stress in the muscles in the hand.
    Expectation: More room for improvement.


The text below is taken from the Terry Pratchett quote file and Cartoon Laws. While this text isn't very representative for the context for Yashid, is will have to do for now.

Let's just say that if complete and utter chaos was lightning, he'd be the sort to stand on a hilltop in a thunderstorm wearing wet copper armour and shouting "All gods are bastards". -- Rincewind discussing Twoflower (Terry Pratchett, The Colour of Magic)

Cartoon Law III. Any body passing through solid matter will leave a perforation conforming to its perimeter. Also called the silhouette of passage, this phenomenon is the speciality of victims of directed-pressure explosions and of reckless cowards who are so eager to escape that they exit directly through the wall of a house, leaving a cookie-cutout- perfect hole. The threat of skunks or matrimony often catalyzes this reaction.