David Nunez

Preserving Spatial and Temporal Dimensions in Observational Data of Segregation

Recent approaches to the study of intergroup contact have emphasised the need for naturalistic studies and the importance of paying attention to the spatiality of contact. In this article it is argued that it is important to preserve both spatiality and temporality when studying inter-group contact in naturalistic settings. This is not easy to do with existing observational methods, and a novel approach is proposed. Photographs are taken of a public space with a fixed periodicity and vantage point, and with knowledge of the physical layout of the space, three-dimensional, time-marked data points are recorded for each inhabitant. A public space on a university campus was used as a test bed, and data are reported that show it to be very useful, giving fresh insights into the nature of segregation and integration in informal leisure spaces, as well as providing evidence of the importance of taking temporality into account when studying naturalistic instances of inter-group contact.

Cognitive presence as a unified concept of virtual reality effectiveness

We propose a synthesis of two current major approaches to understanding the effectiveness of VR systems. We propose cognitive presence as a single, unified concept of presence which includes previous ideas of presence in a cognitive psychological framework, and propose a methodology for measuring it. We then critically examine the notion of cognitive presence, as a way of conceptualizing HCI quality in virtual environments.

Predicting Eyewitness Identification Accuracy with Mock Witness Measures of Lineup Fairness: Quality of Encoding Interacts with Lineup Format

After viewing a staged crime under varying levels of encoding optimality, eyewitnesses made identifications from lineups that were either presented to them as a simultaneous line of people, or individually, in sequence. Lineups did not contain the perpetrator of the staged crime, and were purposefully constructed to have varying levels of bias. There was an interaction between encoding optimality and type of lineup, with sequential-presentation lineups leading to more correct rejections than simultaneous-presentation lineups for moderate encoding optimality. Sequential-presentation lineups did not provide good protection against mistaken identifications in the two other conditions of encoding optimality. Measures of the fairness of the lineups significantly predicted identification rates for both simultaneous-presentation lineups and sequential-presentation lineups, regardless of encoding optimality.

A direct comparison of presence levels in text-based and graphics-based virtual environments

We present results from an experiment (n=78) which used two presence measures to directly compare presence in text-based and graphics-based VEs of two levels of quality. The results show that text-based VEs produce less presence than graphics-based VEs, but the actual difference is less than 20%. This finding has implications for those wishing to implement VEs in impoverished devices or those working towards understanding the cognitive processing of VEs.