Stefano Padilla

Perceived roughness of 1/fβ noise surfaces

We report results from a new methodology for investigating the visually perceived properties of surface textures. Densely sampled two-dimensional 1/f(beta) noise processes are used to model natural looking surfaces, which are rendered using combined point-source and ambient lighting. Surfaces are shown in motion to provide rich cues to their relief. They are generated in real time to enable observers to dynamically manipulate surface parameters. A method of adjustment is employed to investigate the effects that the two surface parameters, magnitude roll-off factor and RMS height, have on perceived roughness. The results are used to develop an estimation method for perceived roughness.

Crowdsourced Feedback With Imagery Rather Than Text: Would Designers Use It?

Cognitive styles theories suggest that we divide into visual and verbal thinkers. In this paper we describe a method designed to encourage visual communication between designers and their audiences. This new visual feedback method is based on enabling fast intuitive selections by the crowd from image banks when responding to an idea. Visual summarization reduces the massed image choices to a small number of representative images. These summaries are then consumed at a glance by designers receiving the feedback leading to thoughtful reflection on their designs. We report an evaluation using two types of imagery for feedback. Twelve designers took part, receiving visual feedback in response to their designs. In semi-structured interviews they described their interpretation of the feedback, how it inspired them to change their designs and contrasted it with text feedback. Eleven of the twelve designers revealed that they would be enthusiastic users of a service providing this new mode of feedback.

The affective experience of handling digital fabrics: tactile and visual cross-modal effects

In the textile sector, emotions are often associated with both physical touch and manipulation of the product. Thus there is the need to recreate the affective experiences of touching and interacting with fabrics using commonly available internet technology. New digital interactive representations of fabrics simulating handling have been proposed with the idea of bringing the digital experience of fabrics closer to the reality. This study evaluates the contribution of handling real fabrics to viewing digital interactive animations of said fabrics and vice versa. A combination of self-report and physiological measures was used. Results showed that having previous physical handling experience of the fabrics significantly increased pleasure and engagement in the visual experience of the digital handling of the same fabrics. Two factors mediated these experiences: gender and interoceptive awareness. Significant results were not found for the opposite condition.

Intuitive Large Image Database Browsing Using Perceptual Similarity Enriched by Crowds

The main objective of image browsers is to empower users to find a desired image with ease, speed and accuracy from a large database. In this paper we present a novel approach at creating an image browsing environment based on human perception with the aim of providing intuitive image navigation. In our approach, similarity judgments form the basic structural organization for the images in our browser. To enrich this we have developed a scalable crowd sourced method of augmenting a database with a large number of additional samples by capturing human judgments from members of a crowd. Experiments were conducted involving two databases that demonstrate the effectiveness of our method as an intuitive, fast browsing environment for large image databases.

A Picture Paints a Thousand Words but Can it Paint Just One

Imagery and language are often seen as serving different aspects of cognition, with cognitive styles theories proposing that people can be visual or verbal thinkers. Most feedback systems, however, only cater to verbal thinkers. To help rectify this, we have developed a novel method of crowd communication which appeals to those more visual people. Designers can ask a crowd to feedback on their designs using specially constructed image banks to discover the perceptual and emotional theme perceived by possible future customers. A major component of the method is a summarization process in which the crowds feedback, consisting of a mass of images, is presented to the designer as a digest of representative images. In this paper we describe an experiment showing that these image summaries are as effective as the full image selections at communicating terms. This means that designers can consume the new feedback confident that it represents a fair representation of the total image feedback from the crowd.

I Don't Think We've Met: Encouraging Collaboration via Topic-Based Search

We present PaperPilot1 (bit.ly/paperpilot) a new tool which performs smart collaborator search using research concepts automatically extracted from the CSCW domain, as characterized by 5,516 papers taken from four conferences in the area. PaperPilot infers how a paragraph of text (say an abstract or news article) relates to these research concepts and uses this information to retrieve the 100 most similar papers and identify the most relevant topic for each. These topics can be used both to obtain a quick overview of the papers and as an ice breaker for opening conversations with potential collaborators. To ensure the smart collaborator search is relevant to CSCW 2015 attendees, all accepted papers and authors will also be included.

Perceived directionality of 1/ f β noise surfaces

We are investigating the perceived characteristics of 3D surface texture by using rendered images of synthetic surfaces with precisely defined characteristics. We compute texture features directly from the height data and present observers with animated images that mimic the way in which people rotate surface textures when assessing their characteristics. This both eliminates illumination induced bias and provides observers with rich, realistic stimuli.

Understanding Concept Maps: A Closer Look at How People Organise Ideas

Research into creating visualisations that organise ideas into concise concept maps often focuses on implicit mathematical and statistical theories which are built around algorithmic efficacy or visual complexity. Although there are multiple techniques which attempt to mathematically optimise this multi-dimensional problem, it is still unknown how to create concept maps that are immediately understandable to people. In this paper, we present an in-depth qualitative study observing the behaviour and discussing the strategy used by non-expert participants to create, interact, update and communicate a concept map that represents a collection of research ideas. Our results show non-expert individuals create concept maps differently to visualisation algorithms. We found that our participants prioritised narrative, landmarks, abstraction, clarity, and simplicity. Finally, we derive design recommendations from our results which we hope will inspire future algorithms that automatically create more usable and compelling concept maps better suited to the natural behaviours and needs of users.

What To Study In HCI? A Reflection Based On CHI and UK Research Data

HCI is a wide, varied, and complex field that covers a broad spectrum of research. We therefore believe that there is no simple answer to the question ‘what to study in HCI?’ To shed some light on it, however, we reflect on this question with the aid of data from past HCI conferences, present meta-analyses reports, and possible future research priorities. In our discussion, we argue that the current focus of HCI research is too focused on studying the usability of gadgets. Instead, we believe that researchers in the HCI field have the unique opportunity to combine fundamental research, usability design, and awareness of social issues to achieve real-world impact. As such, we suggest that researchers should aim their studies on human aspects that can solve various needs, problems, and societal challenges. Author