|
Visual Impairments:
Students with visual impairments include students who are blind, have limited
vision, or have color deficiency (color blind). In order for software to be
accessible to these students, it must follow a simple and logical navigation
structure, contain textual descriptions of images, offer navigation solely
through a keyboard (without a mouse), provide information about text boxes, and
allow the student to customize color and contrast preferences.
Navigation throughout the software must be simple and logical. Most pieces of
instructional software base their navigation on visual cues. For instance, "move
ahead" arrows are usually placed on the bottom right of the screen, and "go
back" buttons are often placed on the bottom left. Navigation must also make
sense to a user who can't see these location clues. Another accessibility
concern is that screen readers cannot "read" images; a description of the image
is essential so that a student who cannot see it can still understand the
information the image presents. Screen readers also need to be able to identify
what information is needed to complete a pull down menu or text box and whether
a radio button is "on" or "off." Another important accessibility function is the
use of color. It cannot be the sole way of communicating an idea. For instance,
stop buttons should have the word "stop" over the top of the red sign. Graphs
should offer pattern differentiation as well as color differentiation. Finally,
instructional software must allow students to customize text size, color, and
contrast preferences. |
