Lessons learned from evaluating eight password nudges in the wild

Background. The tension between security and convenience, when creating passwords, is well established. It is a tension that often leads users to create poor passwords. For security designers, three mitigation strategies exist: issuing passwords, mandating minimum strength levels or encouraging better passwords. The first strategy prompts recording, the second reuse, but the third merits further investigation. It seemed promising to explore whether users could be subtly nudged towards stronger passwords.Aim. The aim of the study was to investigate the influence of visual nudges on self-chosen password length and/or strength.Method. A university application, enabling students to check course dates and review grades, was used to support two consecutive empirical studies over the course of two academic years. In total, 497 and 776 participants, respectively, were randomly assigned either to a control or an experimental group. Whereas the control group received no intervention, the experimental groups were presented with different visual nudges on the registration page of the web application whenever passwords were created. The experimental groups’ password strengths and lengths were then compared that of the control group.Results. No impact of the visual nudges could be detected, neither in terms of password strength nor length. The ordinal score metric used to calculate password strength led to a decrease in variance and test power, so that the inability to detect an effect size does not definitively indicate that such an effect does not exist.Conclusion. We cannot conclude that the nudges had no effect on password strength. It might well be that an actual effect was not detected due to the experimental design choices. Another possible explanation for our result is that password choice is influenced by the user’s task, cognitive budget, goals and pre-existing routines. A simple visual nudge might not have the power to overcome these forces. Our lessons learned therefore recommend the use of a richer password strength quantification measure, and the acknowledgement of the user’s context, in future studies

DAIRY FARMS IN MICHIGAN'S U.P., 2001

Livestock Production/Industries,

Design for rituals of letting go:an embodiment perspective on disposal practices informed by grief therapy

People increasingly live their lives online, accruing large collections of digital possessions, which symbolically represent important relationships, events, and activities. Most HCI research on bereavement focuses on retaining these significant digital possessions to honor the departed. However recent work suggests that significant digital possessions may complicate moving on; they function as both comforting and painful reminders but currently provide inflexible methods for disposal. Little work has investigated the disposal of digital objects as a means of letting go. To better understand this we interviewed 10 psychotherapists who employ rituals of letting go to help patients overcome loss in situations such as a divorce, a breakup, or a stillbirth. Patients disposed of either natural artefacts or symbolic personal possessions through actions such as burning, burying, or placing in a body of water. Therapists noted people increasingly have digital possessions, and that the act of deletion does not offer the same cathartic sense of release as disposal of material artefacts. Based on analysis of this grief therapy, we propose a new conceptual framework for rituals of letting go that highlights temporality, visibility, and force. It provides a vocabulary to talk about disposal. We then offer design implications connecting the rituals of letting go to the disposal of digital things. Based on our interviews and analytic framework, we propose novel technologies that better connect the embodied nature of letting go rituals to the process of digital disposal

Design of the advanced regional aircraft, the DART-75

This design analysis is intended to show the capabilities of the DART-75, a 75 passenger medium-range regional transport. Included are the detailed descriptions of the structures, performance, stability and control, weight and balance, and engine design. The design should allow for the DART to become the premier regional aircraft of the future due to some advanced features like the canard, semi-composite construction, and advanced engines

A Psychophysical Comparison of Two Methods for Adaptive Histogram Equalization

Adaptive histogram equalization (ahe) is a method for adaptive contrast enhancement of digital images propped by Pizer et. Al.. It has the properties that it is an automatic, reproducible method for the simultaneous viewing of contrast within a digital image with a large dynamic range. Recent experiments have show that in specific cases, there is no significant difference in the ability of ahe and linear intensity windowing to display grey-scale contrast. More recently, Pizer et al. have proposed a variant of ahe which limits the allowed contrast enhancement of the image. The contrast-limited adaptive histogram equalization (clahe) produces images in which the noise content of an image is nor excessively enhanced, but in which sufficient contrast is provided for the visualization of structures within the image. Images processed with clahe have a more natural appearance and facilitate the comparison of different areas of an image. However, the reduced contrast enhancement of clahe may hinder the ability of an observer to detect the presence of some significant grey-scale contrast. In this work, a psychophysical observer experiment was performed to determine if there is a significant difference in the ability of ahe and clahe to depict grey-scale contrast. Observers were presented with CT images of the chest processed with ahe and clahe into some of which subtle artificial lesions were introduced. The observers were asked to rate their confidence regarding the presence of the lesions; this rating-scale data was analyzed using Receiver Operating Characteristic curving techniques. These ROC curves were compared for significant differences in the observers\u27 performances. In this study, no difference was found in the abilities of ahe and clahe to depict contrast information

The zebrafish mutant dreammist implicates sodium homeostasis in sleep regulation

Sleep is a nearly universal feature of animal behaviour, yet many of the molecular, genetic, and neuronal substrates that orchestrate sleep/wake transitions lie undiscovered. Employing a viral insertion sleep screen in larval zebrafish, we identified a novel gene, dreammist (dmist), whose loss results in behavioural hyperactivity and reduced sleep at night. The neuronally expressed dmist gene is conserved across vertebrates and encodes a small single-pass transmembrane protein that is structurally similar to the Na+,K+-ATPase regulator, FXYD1/Phospholemman. Disruption of either fxyd1 or atp1a3a, a Na+,K+-ATPase alpha-3 subunit associated with several heritable movement disorders in humans, led to decreased night-time sleep. Since atpa1a3a and dmist mutants have elevated intracellular Na+ levels and non-additive effects on sleep amount at night, we propose that Dmist-dependent enhancement of Na+ pump function modulates neuronal excitability to maintain normal sleep behaviour

An epitope-specific DerG-PG70 LEAPS vaccine modulates T cell responses and suppresses arthritis progression in two related murine models of rheumatoid arthritis

L