Anke Huckauf

The GlobeFish and the GlobeMouse: two new six degree of freedom input devices for graphics applications

We introduce two new six degree of freedom desktop input devices based on the key concept of combining forceless isotonic rotational input with force-requiring elastic translational input. The GlobeFish consists of a custom three degrees of freedom trackball which is elastically connected to a frame. The trackball is accessible from the top and bottom and can be moved slightly in all spatial directions by using force. The GlobeMouse device works in a similar way. Here the trackball is placed on top of a movable base, which requires to change the grip on the device to switch between rotating the trackball and moving the base.Our devices are manipulated with the fingertips allowing precise interaction with virtual objects. The elastic translation allows uniform input for all three axes and the isotonic trackball provides a natural mapping for rotations. Our user study revealed that the new devices perform significantly better in a docking task in comparison to the SpaceMouse, an integrated six degrees of freedom controller. Subjective data confirmed these results.

Gazing with pEYEs: towards a universal input for various applications

Various interfaces for gaze control (which are recommended due to certain requirements of controlling a machine by gaze) have already been developed. One problem, especially for novice users, is that respective interfaces all look different and require different steps to use. As a means to unify interfaces for gaze control, pie menus are suggested. Such pEYEs allow for universal input in various applications usable by novices and by experts. We present two examples for pEYE interfaces; one eye-typing application and one desktop navigation. Observations in user studies indicate effective and efficient performance and a large acceptance.

Lateral masking: Limitations of the feature interaction account

Recognition performance for a target letter embedded in a string of characters is worse than that for targets presented in isolation. This lateral masking (LM) effect is known to depend on target eccentricity and spacing between target and flankers (Bouma, 1970), indicating that LM arises in early visual processing due to interactions among visual features. The feature interaction account would predict that flankers consisting of similar features produce similar LM effects and that differences in LM produced by different types of flanker diminish with increasing target eccentricity and decreasing spacing. However, in a series of six experiments, this prediction was shown not to be true. Flankers that did not ac-cess a higher level code (e.g., pseudoletters or rotated letters) produced more LM than standard letter flankers. Moreover, effects of different flanker types were most pronounced for medium target eccentricities and medium spacings for which recognition performance scores ranged between 40% and 60%.

What various kinds of errors tell us about lateral masking effects

Error analyses were conducted to study processes underlying lateral masking effects. Location errors (i.e., confusions with a flanking letter) occurred at a rate higher than chance, and they increased with increasing eccentricity and with decreasing spacing. In longer strings, confusions with a flanker directly adjacent to the target (which is itself laterally masked) were more frequent than with a far flanker, and these confusions also increased with increasing eccentricity and with decreasing spacing indicating that identification of the letters form is not necessarily disturbed by adjacent characters. This was confirmed in a whole report task, where there was better recognition performance for the central letter than in partial report. Whereas in partial report, the left flanker was more often confused with the target than the right one, in whole report, the left-most letter was recognized best. The data provide evidence that positional uncertainty contributes to lateral masking effects, and that a substantial portion of positional uncertainty occurs after having identified the letters forms.

How odgcrnwi becomes crowding: Stimulus-specific learning reduces crowding

Processes underlying crowding in visual letter recognition were examined by investigating effects of training. Experiment 1 revealed that training reduces crowding mainly for trained strings. This was corroborated in Experiment 2, where no training effects were obvious after 3 days of training when strings changed from trial to trial. Experiment 3 specified that after a short amount of training, learning effects remained specific to trained strings and also to the trained retinal eccentricity and the interletter spacing used in training. Transfer to other than trained conditions was observed only after further training. Experiment 4 showed that transfer occurred earlier when words were used as stimuli. These results thus demonstrate that part of crowding results from the absence of higher level representations of the stimulus. Such representations can be acquired through learning visual properties of the stimulus.

Spatial selection in peripheral letter recognition: in search of boundary conditions.

Recognition performance for a peripherally presented target letter embedded in a letter string is worse than for targets presented in isolation. This lateral masking effect is commonly attributed to impairments when identifying flanked letters. The hypothesis that also failures during spatial selection of the target underlie lateral masking effects was examined by varying the brightness of the flankers (Experiment 1), by cueing the target position at various times before, during, or after presentation of the string (Experiment 2) and by avoiding the abrupt on- and offset of the flankers (Experiments 3 and 4). Whereas the flankers brightness had no effect on and cueing only slightly reduced the lateral masking effects, it was substantially reduced by avoiding the abrupt on- and offset of the flankers. The results show that spatial selection is impaired in peripheral vision, and that this is one important factor underlying lateral masking effects.

Mobile Augmented Reality in industrial applications: Approaches for solution of user-related issues

Augmented Reality (AR) uses computer-generated virtual information to enhance the userpsilas information access. While numerous previous studies have demonstrated the large potential of AR to improve industrial processes by enhancing product quality and reducing production times it is still unclear if and how long term usage of such AR technology produces stress and strain. This paper presents an approach to use the analysis of Heart Rate Variability to objectively measure current user strain during different work tasks. Results of a user study comparing strain during an AR supported and a non-AR supported work task in a laboratory setting are presented and discussed.

On the relations between crowding and visual masking

To study the question of which processes contribute to crowding and whether these are comparable to those of visual temporal masking, we varied the stimulus onset asynchrony (SOA) between target and flankers in a crowding setting. Monotonically increasing Type A masking functions observed for small spacings and large eccentricities indicate that the integration of information from target and flankers underlies crowding. Decreasing masking functions obtained for large spacings and small eccentricities relate processes of crowding to those contributing to Type B masking. In addition, Type B masking was more frequent with letter-like nonletter flankers than with letter flankers, suggesting that Type B masking, just like crowding over large areas, is due to higher level interactions. The rapid decrease of the effects of interletter spacing and eccentricity with increasing SOA indicates that positional information is transient.

On 3D input devices

We provide an overview of some of our input device developments, which we designed in response to the need for more advanced 3D interfaces. Some of our devices are more task-specific and others are more general, but all of them support six or more degrees of freedom (DOF) and work in three dimensions. In our work, we try to understand the essential requirements of individual tasks and task combinations to develop corresponding devices and interaction techniques. This is our way of developing input devices for the 3D domain that work better for certain application areas than 2D mouses, gloves, and wands.

Gazing with pEYE: new concepts in eye typing

Eye typing applications like a virtual keyboard are often straining to use. We developed various interfaces based on different theoretical ideas. In Iwrite, letters are selected by gazing towards the outer frame of the monitor. This should minimize the error rate, but to the disadvantage of speed. In a dynamic concept, StarWrite, moving letters are to be dragged directly onto the text window. The third implementation pEYEwrite is based on marking or pie menus which have already been shown to be powerful tools in mouse control. Preliminary testings demonstrated a superiority of pEYEwrite over the other concepts. Not only did pEYEwrite produce the fastest text entry, but also the largest increases in performance over several sessions. Data indicate that pie menus must be regarded as a helpful and powerful tool in various gaze control applications.