Horizontal Scrolling

Comments Harvey-Walker Article: Reading with peripheral vision: A
comparison of reading dynamic scrolling and static text with a simulated
central <http://www.sciencedirect.com/science/article/pii/S004269891400056X>

The Harvey and Walker article does not support screen magnification without
word wrapping as a mode of accommodation, but it is very interesting. The
paper certainly does describe how I read. I am an eccentric (slant) viewer
owing to my central retina scarring. Their dynamic scrolling that keeps a
controlled fixation point actually describes my adaptation to reading.  I
either use a hand held lens and / or a telescope and move across the page
physically keeping the fixation location in a small range, or I use very
large print on a screen and move my head across the screen also keeping the
fixation point in confined space. Very interesting.
This could be a model for new AT. It would involve totally linear output
like a screen reader. Piping text through the accessibility API could work.
WCAG 2.0  adjustment would be minor. Some screen magnifiers do supply this
with masking all but the active line.

The problems would be self pacing reading and viewport capacity. The
drifting text used by Harvey-Walker is fine for material that is well below
one's intellectual capacity but what content like, "The limit of a function
f(x) is a if and only if for every ε>0 there exists a δ>0 such that |f(x)−a|<ε
whenever |x−a|<δ." This is an elementary but difficult concept. Self paced
reading is necessary. There is also loss of context with the reduced amount
of content to a single line. The entire definition of the limit of a
function can fit in one page wrapped text on a 13 inch laptop at 48pt (3/4
inch) print. Note: that is 480% or 10 point. Even though reading speed and
comprehension could suffer without proper training to keep the fixation
region small as I do, the intellectual context can be maintained. For my
work, mathematics and information technology, context is important.

Comparing the horizontal scrolling of Harvey and Walker to horizontal
scrolling on a screen magnifier is not really accurate. Harvey and Walker
reduce the traversal complexity of reading to get their results. The normal
reading format requires that one must track and scan a two dimensional
object, the page, but one must only scroll in one dimension (vertically
with a screen, horizontally with a book). This is more complex than Harvey
and Walker, but much less complex than zoomed text. The screen magnifier
increases traversal complexity by adding bi-directional scrolling. In terms
of operational complexity, reading using horizontally drifting text in a
single line format is most simple. Normal page navigation comes next with
two dimensional in page traversal and uni-directinal scrolling for page to
page. Magnification is most complex with normal visual tracking and
scanning within the page as well is horizontal scrolling withing the line.
Then there is normal vertical scrolling to go page to page.