Effects of reading span and textual coherence on rapid-sequential reading

Designing an interface to optimize reading with small display windows

The extent of electronic presentation of text in small display windows is mushrooming. In the present paper, 4 ways of presenting text in a small display window were examined and compared with a normal page condition: rapid serial visual presentation (RSVP), RSVP with a completion meter, sentence-by-sentence presentation, and sentence-by-sentence presentation with a completion meter. Dependent measures were reading efficiency (speed and comprehension) and preference. For designers of hardware or software with small display windows, the results suggest the following: (a) Though RSVP is disliked by readers, the present methods of allowing self-pacing and regressions in RSVP are efficient and feasible, unlike earlier tested methods; (b) slower reading in RSVP should be achieved by increasing pauses between sentences or by repeating sentences, not by decreasing the presentation rate within a sentence; (c) completion meters do not interfere with performance and are usually preferred; (d) the space-saving sentence-by-sentence format is as efficient and as preferred as the normal page format.

Simulated cataract does not reduce the benefit of RSVP

Normally sighted younger and older (mean age 71 years) observers read sentences and random lists of words from a rapid serial visual presentation (RSVP) display and a scroll display using their normal vision and through two levels of cataract simulators. Unlike patients with central field loss (CFL), there was no decrease in the benefit of RSVP with reduced vision due to the cataract simulators. However, the usefulness of sentence-level context was reduced as visual acuity was reduced. In addition, older readers did not benefit as much from RSVP as younger readers, and many in the older group were unable to read using the more severe cataract simulators from either display format. From these data we conclude that the benefits of RSVP are not reduced with reduced acuity and contrast sensitivity, and that there are age-related changes in reading rates from dynamic text displays not related to acuity.

Scrolled and rapid serial visual presentation texts are read at similar rates by the visually impaired

Visually impaired observers read dynamically displayed text faster than text displayed in a normal page view. The goal of this study was to compare reading rates from two dynamic-presentation methods that have been proposed to facilitate reading from computer-based displays. Prior research has shown that both normally sighted and low-vision observers read text displayed to the same location, one word at a time [known as rapid serial visual presentation (RSVP)], faster than a page of text. A similar comparison with text scrolled continuously across the screen also shows faster reading for low-vision patients, but the relative change from a standard page view is substantially less (15% faster for the scroll display versus 80% faster for RSVP). In this study we directly compared these techniques. For those with normal vision, reading from the RSVP display was 1.3 times faster than reading from the scroll display [t(9) = 3.32, P = 0.009]. Although the difference in reading rates for the visually impaired group did not reach statistical significance, as a group they read 13% slower from the RSVP than from the scroll display.

Saccadic overhead: information-processing time with and without saccades

Information-processing time was compared for serial and spatially distributed visual presentations with performance measures that permit the separation of total time into its during-display and post-display components. For all subjects, there was a significant saccadic overhead, that is, less time was required with the serial format, which allowed data access without eye movements. However, the magnitude of the overhead decreased as task complexity increased. All subjects were able to exercise some control over the distribution of total processing time, trading off short during-display times with longer post-display times and vice versa.