22 research outputs found
LCD vs. E-ink: An Analysis of the Reading Behavior
Electronic books (e-book) are an interesting option compared to classic paper books. Most e-reading devices of the first generation were based on e-ink technology. With the appearance of the Apple iPad on the market, TFT-LCDs became important in the field of e-reading. Both technologies have advantages and disadvantages but the question remains whether one or the other technology is better for reading. In the present study we analyzed and compared reading behavior when reading on e-inkreader (e-ink displays) and on tablets (TFT-LCDs) as measured by eye-tracking. The results suggest that the reading behavior on tablets is indeed very similar to the reading behavior on e-ink-reader. Participants showed no difference in fixation duration. Significant differences in reading speed and in the proportion of regressive saccades suggest that tablets, under special artificial light conditions, may even provide better legibility
The Illusion of Being Located in Dynamic Virtual Environments. Can Eye Movement Parameters Predict Spatial Presence?
Attention allocation towards the mediated environment is assumed to be a necessary precondition to feel localized in a virtual world. In presence research, however, the potential of eye movement research has not been fully exploited so far. In this study, participants (N=44) rode on a virtual roller coaster simulation. We compare participants scoring high versus low on presence. During the ride, the eye movements and subjective ex post presence judgments were assessed. We found high sensations of presence to be associated with fewer fixations and a tendency towards longer fixation durations. In contrast to the immersive tendency trait, eye movement parameters can predict presence
Non-Redfield carbon and nitrogen cycling in the Arctic: Effects of ecosystem structure and dynamics
The C:N ratio is a critical parameter used in both global ocean carbon models and field studies to understand carbon and nutrient cycling as well as to estimate exported carbon from the euphotic zone. The so-called Redfield ratio (C:N = 6.6 by atoms) [Redfield et al., 1963] is widely used for such calculations. Here we present data from the NE Greenland continental shelf that show that most of the C:N ratios for particulate (autotrophic and heterotrophic) and dissolved pools and rates of transformation among them exceed Redfield proportions from June to August, owing to species composition, size, and biological interactions. The ecosystem components that likely comprised sinking particles and had relatively high C:N ratios (geometric means) included (1) the particulate organic matter (C:N = 8.9) dominated by nutrient-deficient diatoms, resulting from low initial nitrate concentrations (approximately 4 μM) in Arctic surface waters; (2) the dominant zooplankton, herbivorous copepods (C:N = 9.6), having lipid storage typical of Arctic copepods; and (3) copepod fecal pellets (C:N = 33.2). Relatively high dissolved organic carbon concentrations (median 105 μM) were approximately 25 to 45 μM higher than reported for other systems and may be broadly characteristic of Arctic waters. A carbon-rich dissolved organic carbon pool also was generated during summer. Since the magnitude of carbon and nitrogen uncoupling in the surface mixed layer appeared to be greater than in other regions and occurred throughout the productive season, the C:N ratio of particulate organic matter may be a better conversion factor than the Redfield ratio to estimate carbon export for broad application in northern high-latitude systems
Herbivore release through cascading risk effects
Predators influence prey through consumption, and through trait-mediated effects such as emigration in response to predation risk (risk effects). We studied top-down effects of (sub-) adult wolf spiders (Lycosidae) on arthropods in a meadow. We compared risk effects with the overall top-down effect (including consumption) by gluing the chelicers of wolf spiders to prevent them from killing the prey. In a field experiment, we created three treatments that included either: (i) intact (‘predation’) wolf spiders; (ii) wolf spiders with glued chelicers (‘risk spiders’); or (iii) no (sub-) adult wolf spiders. Young wolf spiders were reduced by their (sub-) adult congeners. Densities of sheetweb spiders (Linyphiidae), a known intraguild prey of wolf spiders, were equally reduced by the presence of risk and predation wolf spiders. Plant- and leafhoppers (Auchenorrhyncha) showed the inverse pattern of higher densities in the presence of both risk and predation wolf spiders. We conclude that (sub-) adult wolf spiders acted as top predators, which reduced densities of intermediate predators and thereby enhanced herbivores. Complementary to earlier studies that found trait-mediated herbivore suppression, our results demonstrate that herbivores can be enhanced through cascading risk effects by top predators
Comparing reading processes on e-ink displays and print
E-book reading devices open new possibilities in the field of reading. More activities than just reading a
book can be performed with a single electronic device. For a long time, electronic reading devices have
not been favored because their active LCD displays used to have a relatively low contrast. The new generation
of electronic reading devices differs from earlier ones in the nature of the display: active LCD displays
have been replaced with displays based on e-ink technology, which has display properties closer to
that of printed paper. Moreover, e-ink technology has higher power efficiency, thereby increasing battery
life and reducing weight. At first sight, the display looks similar to paper print, but the question remains
whether the reading behavior also is equal to that of reading a printed book. In the present study, we analyzed
and compared reading behavior on e-reader displays and on printed paper. The results suggest that
the reading behavior on e-readers is indeed very similar to the reading behavior on print. Participants
shared similar proportions of regressive saccades while reading on e-readers and print. Significant differences
in fixation duration suggest that e-readers, in some situations, may even provide better legibility
Reading on LCD vs e-Ink displays: effects on fatigue and visual strain
Purpose:  Most recently light and mobile reading devices with high display resolutions have become popular and they may open new possibilities for reading applications in education, business and the private sector. The ability to adapt font size may also open new reading opportunities for people with impaired or low vision. Based on their display technology two major groups of reading devices can be distinguished. One type, predominantly found in dedicated e-book readers, uses electronic paper also known as e-Ink. Other devices, mostly multifunction tablet-PCs, are equipped with backlit LCD displays. While it has long been accepted that reading on electronic displays is slow and associated with visual fatigue, this new generation is explicitly promoted for reading. Since research has shown that, compared to reading on electronic displays, reading on paper is faster and requires fewer fixations per line, one would expect differential effects when comparing reading behaviour on e-Ink and LCD. In the present study we therefore compared experimentally how these two display types are suited for reading over an extended period of time.
Methods:  Participants read for several hours on either e-Ink or LCD, and different measures of reading behaviour and visual strain were regularly recorded. These dependent measures included subjective (visual) fatigue, a letter search task, reading speed, oculomotor behaviour and the pupillary light reflex.
Results:  Results suggested that reading on the two display types is very similar in terms of both subjective and objective measures.
Conclusions:  It is not the technology itself, but rather the image quality that seems crucial for reading. Compared to the visual display units used in the previous few decades, these more recent electronic displays allow for good and comfortable reading, even for extended periods of time
The Relationship between Flexible and Self-Regulated Learning in Open and Distance Universities
Flexibility in learning provides a student room for volitional control and an array of strategies and encourages persistence in the face of difficulties. Autonomy in and control over one’s learning process can be seen as a condition for self-regulated learning. There are a number of categories and dimensions for flexible learning; following professional publications, time, location, lesson content, pedagogy method, learning style, organization, and course requirements are all elements to consider. Using these categories and the dimensions of flexible learning, we developed and validated a questionnaire for an open and distance learning setting. This article reports on the results from a study investigating the relationship between flexible learning and self-regulated learning strategies. The results show the positive effects of flexible learning and its three factors, time management, teacher contact, and content, on self-regulated learning strategies (cognitive, metacognitive, and resource-based). Groups that have high flexibility in learning indicate that they use more learning strategies than groups with low flexibility