UCIT_2_.ppt 508KB Jun 23 2011 12:33:34 PM

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Visualization of textual information

for people with special needs

10.01.2004

Presentation for UCIT seminar Tatiana Evreinova

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Contents



Main research tasks for 2003 and 2004 (1)



Pseudo-graphic typeface



initial study (8)



readability study in dynamically displayed mode:



testing and apparatus (2)

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results, drawbacks and prospective applications (6)

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Forthcoming research: design of vibro-tactile alphabet (3)

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Two main research problems

– Usability evaluation of the pseudo-graphic typeface

(4)

Pseudo - Graphic Typeface:

Design and Evaluation

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Problems

– lip reading requires a great concentration of visual

attention and can be very stressful

– even qualified sign language interpreters cannot

interpret everything in group situations

– the usage of subtitling signing has a high level of

transmission difficulties and still remains as an

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experimental setup

Goals

– to develop communication techniques through

graphical imaging of textual information for the

profoundly deaf and hard-of-hearing people

– to find out an approach that would require minimum

resources of visual perception by using pseudo-graphic

tokens; these tokens must be perceived preattentively

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Design

(1/2)

(8)

Design

(9)

– constructive research to design and simulate the new techniques

for textual imaging, software tools and algorithms for visibility

evaluation of graphic tokens

– empirical research based on tracking of the eye movements

subjective / objective evaluation:

tachistoscopic evaluation

visual scan time measurement

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Materials

Selected

Typefaces

Motivation to select the

typeface

Arial

The most commonly used sans serif font (1, 2, 3)

Comic

The mimic print facilitates syllabic tokens perception (1)

Courier

The most commonly used mono-spaced font (3)

Impact

Easy to perceive on screen, a large x-height factor (2, 4)

Times New

High legibility with economy of screen space (2)

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Resource

s

SMI Eye-Gaze tracking system allows recording eye movements

iComponent provides a possibility to use SMI Eye_Gaze data in other

application through a simple interface [developed by Oleg Spakov]

iView 3.01 program processes SMI Eye_Gaze data and displays

saccadic movements (row data), fixations and scanpaths

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Generalization of obtained results

A higher number of AVI observed for phonetic typefaces (5-7) and lower one for Styled typeface (only 4) confirms that explored typeface

is more easily perceived.

Impact and Styled seemed to be more legible than Courier, Arial, Comic and Times New Roman and being the most preferred, could be perceived fairly preattentively.

Subjects had fewer recognition difficulties for Arial and Times New Roman typefaces.

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Pseudo - Graphic Typeface:

Readability study in dynamically displayed mode

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Testing

– Eight volunteers from staff and students at the University

of Tampere took part in the testing and were recruited

from those subjects who participated in previous study

– Tested subjects were needed about 2 hours to learn the

whole alphabet

– Formal experiment had taken one week

– 20 words per each block to measure alphabet readability

– 3 trials per each exposition time, 4 blocks per one session

– Four exposition times were examined (320, 400, 480 and

640 ms per token)

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Apparatus

snapshot of the software in editorial mode

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Results / Reading comprehension

Reading comprehension score to 7th_{session (X-axis) by one of subjects was}

measured by number of repeated playbacks (Y-axis) needed to recognize textual passage

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Results / Reading time

Reading time in seconds (X-axis) needed to recognize textual

passages having different number of characters (Y-axis), first (A) and seventh (B) sessions (longer bars indicate longer reading time)

A

B

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Results / Comprehension accuracy

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Results / Subjective ratings

Post-test questionnaire results (n = 8)

Subjects were more satisfied with reading textual passages at presentation rates 640 and 480 ms per token.

They felt eyestrain with the reading typeface at presentation rate of 400 ms Seven of eight subjects felt positive of using this typeface on the regular basis

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Drawbacks

– A problem to distinguish repeated patterns during of

dynamic presentation (for example in the words “pa

tt

ern”

or “l

oo

k”)

– It is difficult to follow the changing of letters because of

different directions they have

– Subjects get quickly tired with reading of the

pseudo-graphic typeface at higher presentation rates and even

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Prospective

applications

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Forthcoming research: Design of

vibro-tactile alphabet

tactile alphabet

(1/3)

The perception of vibro-tactile patterns occurs in the tactile analyzer using similar algorithms through which the visual system processes a temporal structure of the afferent flow.

The dynamic range for tactile analyzer is narrow in comparison to its visual and auditory counterparts, however the number of possible states of an afferent flow at the time of stimulation of tactile receptors can have many more levels than was previously observed (more than 125).

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Forthcoming research

(2/3)

I propose to design a specific vibro-tactile alphabet oriented on

the stimulation of the tactile receptors of touch and skin to

develop an alternative communication technique through

vibro-tactile imaging of the textual information for the profoundly deaf

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Forthcoming research

(3/3)

A new Grigori Evreinov’s game for training tactile feedback (1, 2, 3 – game levels)

Developed software simplifies learning and validation of the system of vibration tactones and strengthens fingertips sensitivity.

The tool allows validation of the nine tactones.

Three groups of the tactons for the vibro-tactile alphabet imaging will be examined.

Using the game mode facilitates direct usability testing and systematic data collection as well as it decreases subjective workload during the experiment.

1

2

3

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References

[1] Bernard M., Mills M., Frank T., McKown J (2001). Which font do children prefer

to read online? Usability News 3.1.

[2] Boyardski D., Neuwirth C., Forlizzi J., Regli (1998). A study of fonts designed

for screen display. In proceedings of CHI’ 98, (April 18-23, Los Angeles), pp. 87-94.

[3] Evreinova Tatiana and Roope Raisamo. Communication aid based on

pseudo-graphic typeface: readability study in continuous mode. Will be submitted to the

IFHOH 7th_{World Congress, which will be held in Helsinki, Finland from the 4}th_{July to}

the 7th_{July 2004, 8 pp. (full paper).}

[4] Evreinov Grigori, Evreinova Tatiana and Roope Raisamo. Games for training

tactile memory. Late-breaking results, 4 pp. (full paper).

[5] Mills C. B. & Weldon L. J (1987). Reading text from computer screens. ACM

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Thanks for your attention

Questions?