One of the recent trends in computer input is to utilize users' natural bimanual motor skills. This paper further explores the potential benefits of such two-handed input. We have observed that bimanual manipulation may bring two types of advantages to human-computer interaction: manual and cognitive. Manual benefits come from increased time-motion efficiency, due to the twice as many degrees of freedom simultaneously available to the user. Cognitive benefits arise as a result of reducing the load of mentally composing and visualizing the task at an unnaturally low level imposed by traditional unimanual techniques. Area sweeping was selected as our experimental task. It is representative of what one encounters, for example, when sweeping out the bounding box surrounding a set of objects in a graphics program. Such tasks can not be modelled by Fitts' Law alone (Fitts, 1954) and have not been previously studied in the literature. In our experiments, two bimanual techniques were compared with the conventional one-handed GUI approach. Both bimanual techniques employed the two-handed "stretchy" technique first demonstrated by Krueger (1983). We also incorporated the "Toolglass" technique introduced by Bier, Stone, Pier, Buxton and DeRose (1993). Overall, the bimanual techniques resulted in significantly faster performance than the status quo one-handed technique, and these benefits increased with the difficulty of mentally visualizing the task, supporting our bimanual cognitive advantage hypothesis. There was no significant difference between the two bimanual techniques. This study makes two types of contributions to the literature. First, practically we studied yet another class of transaction where significant benefits can be realized by applying bimanual techniques. Furth...

Abstract: The bulk of applications for haptic feedback employ direct rendering approaches wherein a user touches a virtual model of some “real ” thing, often displayed graphically as well. We propose a new class of applications based on abstract messages, ranging from “haptic icons ” – brief signals conveying an object’s or event’s state, function or content – to an expressive haptic language for interpersonal communication. Building this language requires us to understand how synthetic haptic signals are perceived, and what they can mean to us. Experiments presented here address the perception question by using an efficient version of Multidimensional Scaling (MDS) to extract perceptual axes for complex haptic icons: once this space is mapped, icons can be designed to maximize both differentiability and individual salience. Results show that a set of icons constructed by varying the frequency, magnitude and shape of 2-sec, time-invariant wave shapes map to two perceptual axes, which differ depending on the signals ’ frequency range; and suggest that expressive capability is maximized in one frequency subspace.

Rationality is a complex behavioral theory that can be parsed into statements about preferences, perceptions, and process. This paper looks at the evidence on rationality that is provided by behavioral experiments, and argues that most cognitive anomalies operate through errors in perception that arise from the way information is stored, retrieved, and processed, or through errors in process that lead to formulation of choice problems as cognitive tasks that are inconsistent at least with rationality narrowly defined. The paper discusses how these cognitive anomalies influence economic behavior and measurement, and their implications for economic analysis.

Three experiments were conducted to investigate contextual effects and response mode effects (e.g., preference reversals) in risky decision making. Judgments of the worth of binary gambles were examined using two different contexts (positively and negatively skewed distributions of expected values) and two different response modes (attractiveness ratings and buying prices). Changes in the response mode affected the preference order of gambles, and changes in the context due to variations in skewing influenced the metric properties of the judgments but had a minimal effect on preference orders. Data were inconsistent with contingent weighting theory (Tversky, Sattath, & Slavic, 1988) and expression theory (Goldstein & Einhom, 1987). Results could be described by a change-of-process theory which assumes that the method of elicitation influences the manner in which people combine information and arrive at judgments. Under certain conditions, attractiveness ratings could be described by an additive combination of subjective probability and utility (s and u), whereas pricing judgments were accounted for by a multiplicative function, with the same scales of s and u in both tasks. When the range of outcomes included zero and negative values, preference orders for attractiveness ratings of gambles changed. This change in rank order was consistent with the hypothesis that inclusion of these levels caused more subjects to use a multiplicative rule for combining u and s when rating the attractiveness of gambles. Thus, preference reversals can be explained by the theory that the combination rule changes, while utilities and subjective probabilities remain constant. 0 1992 Academic Press, h. Requests for reprints should be addressed to Barbara A. Mellers, Department of Psychology,

In between-subjects (BS) designs, different groups may be asked to make judgments on numerical rating scales. According to judgment theory, judgments obtained BS are not an ordinal scale of subjective value. This article illustrates how BS designs can lead to strange conclusions: When different groups judge the subjective size of numbers, 9 is judged significantly larger than 221. The theory is that 9 brings to mind a context of small numbers, among which 9 seems "average" or even "large"; however, 221 invokes a context of 3-digit numbers, among which 221 seems relatively "small. " Within-subjects, however, judges would not have said 9> 221. Implications of this problem and suggestions for dealing with it are discussed. The purpose of this article is to illustrate how between-subjects (BS) experiments, in which the dependent variable is a judgment, can lead to dubious conclusions. Although this point has been made

In this investigation of monocular perception of egocentric distance, the authors advocate the necessity of a perception-action approach because calibration is intrinsic to definite distance perception. A helmet-mounted camera and display were used to isolate optic flow generated by participants ' head movements toward a target, and participants ' reaches to place a stylus either in a target hole (Experiments 1, 2, and 4) or aligned under a target surface (Experiment 3) were analyzed. Conclusions are that binocular distance perception is accurate, monocular distance perception yields compression that is not eliminated by feedback, but feedback is used to eliminate underestimation generated by restriction of the size of the visual field. The study of definite distance perception requires a perception-action approach. As we argue, the reason is twofold. First, definite distance perception entails calibration and, therefore, a task-specific action that provides both feedback and a standard of accuracy. Calibration is complete once measurements are within a task-specific tolerance. The tolerance is determined by error variability and task requirements,

In response to the paper "Joint commentary on "The Importance of Duration in Ratings of, and Choices Between, Sequences of Outcomes" Kahneman wrote a commentary, and Ariely and...

This paper examines possible barriers to securitization, focusing on behavioral responses to such novel instruments. These barriers include the difficulties of conveying the associated risks, even to investors who are sophisticated about finance (but still uncertain about model risk and structural uncertainties). Our analyses will draw on results in behavioral decision making and psychology. They will lead to proposals for empirical research and general strategies for making securities design more consonant with investor behavior.

The terminology in current use for perceptual matters is varied and often confusing, particularly for size and distance. The symbols used for psychophysical formulae are also not standardised. Uniformity would help to establish psychophysics as a recognised science.

In a trio of experiments, a matching procedure generated direct, analogue measures of short-term memory for the spatial frequency of Gabor stimuli. Experiment 1 showed that when just a single Gabor was presented for study, a retention interval of just a few seconds was enough to increase the variability of matches, suggesting that noise in memory substantially exceeds that in vision. Experiment 2 revealed that when a pair of Gabors was presented on each trial, the remembered appearance of one of the Gabors was influenced by: (i) the relationship between its spatial frequency and the spatial frequency of the accompanying, task-irrelevant non-target stimulus; and (ii) the average spatial frequency of Gabors seen on previous trials. These two influences, which work on very different time scales, were approximately additive in their effects, each operating as an attractor for remembered appearance. Experiment 3 showed that a timely pre-stimulus cue allowed selective attention to curtail the influence of a task-irrelevant non-target, without diminishing the impact of stimuli seen on previous trials. It appears that these two separable attractors influence distinct processes, with perception being influenced by the non-target stimulus, and memory being influenced by stimuli seen on previous trials. Keywords: averaging Visual short-term memory, selective-attention, Prototype effect, perceptual Research on visual working memory has been dominated by a focus on questions of quantity, such as the number of stimuli that can be remembered, or for how long. Although this focus has produced valuable insights (Vogel,