title: Human Visual Navigation: Effects of Visual Context, Navigation Mode, and Gender

authors: Thomson, Diane Marlene

subjects: visual perception

abstract: Abstract

This thesis extends research on human visual path integration using optic flow cues. In three experiments, a large-scale path-completion task was contextualised within highly-textured authentic virtual environments. Real-world navigational experience was further simulated, through the inclusion of a large roundabout on the route. Three semi-surrounding screens provided a wide field of view. Participants were able to perform the task, but directional estimates showed characteristic errors, which can be explained with a model of distance misperception on the outbound roads of the route. Display and route layout parameters had very strong effects on performance. Gender and navigation mode were also influential.

Participants consistently underestimated the final turn angle when simulated self-motion was viewed passively, on large projection screens in a driving simulator. Error increased with increasing size of the internal angle, on route layouts based on equilateral or isosceles triangles. A compressed range of responses was found.

Higher overall accuracy was observed when a display with smaller desktop computer monitors was used; especially when simulated self-motion was actively controlled with a steering wheel and foot pedals, rather than viewed passively. Patterns and levels of error depended on route layout, which included triangles with non-equivalent lengths of the two outbound roads. A powerful effect on performance was exerted by the length of the "approach segment" on the route: that is, the distance travelled on the first outbound road, combined with the distance travelled between the two outbound roads on the roundabout curve. The final turn angle was generally overestimated on routes with a long approach segment (those with a long first road and a 60° or 90° internal angle), and underestimated on routes with a short approach segment (those with a short first road or the 120° internal angle). Accuracy was higher for active participants on routes with longer approach segments and on 90° angle trials, and for passive participants on routes with shorter approach segments and on 120° angle trials. Active participants treated all internal angles as 90° angles. 

Participants performed with lower overall accuracy when optic flow information was disrupted, through the intermittent presentation of self-motion on the small-screen display, in a sequence of static snapshots of the route. Performance was particularly impaired on routes with a long approach segment, but quite accurate on those with a short approach segment. Consistent overestimation of the final angle was observed, and error decreased with increasing size of the internal angle. Participants treated all internal angles as 120° angles.    

The level of available visual information did not greatly affect estimates, in general. The degree of curvature on the roundabout mainly influenced estimates by female participants in the Passive condition. Compared with males, females performed less accurately in the driving simulator, and with reduced optic flow cues; but more accurately with the small-screen display on layouts with a short approach segment, and when they had active control of the self-motion.

The virtual environments evoked a sense of presence, but this had no effect on task performance, in general. The environments could be used for training navigational skills where high precision is not required.

text: Human Visual Navigation: Effects of Visual Context, Navigation Mode, and Gender Abstract

This thesis extends research on human visual path integration using optic flow cues. In three experiments, a large-scale path-completion task was contextualised within highly-textured authentic virtual environments. Real-world navigational experience was further simulated, through the inclusion of a large roundabout on the route. Three semi-surrounding screens provided a wide field of view. Participants were able to perform the task, but directional estimates showed characteristic errors, which can be explained with a model of distance misperception on the outbound roads of the route. Display and route layout parameters had very strong effects on performance. Gender and navigation mode were also influential.

Participants consistently underestimated the final turn angle when simulated self-motion was viewed passively, on large projection screens in a driving simulator. Error increased with increasing size of the internal angle, on route layouts based on equilateral or isosceles triangles. A compressed range of responses was found.

Higher overall accuracy was observed when a display with smaller desktop computer monitors was used; especially when simulated self-motion was actively controlled with a steering wheel and foot pedals, rather than viewed passively. Patterns and levels of error depended on route layout, which included triangles with non-equivalent lengths of the two outbound roads. A powerful effect on performance was exerted by the length of the "approach segment" on the route: that is, the distance travelled on the first outbound road, combined with the distance travelled between the two outbound roads on the roundabout curve. The final turn angle was generally overestimated on routes with a long approach segment (those with a long first road and a 60° or 90° internal angle), and underestimated on routes with a short approach segment (those with a short first road or the 120° internal angle). Accuracy was higher for active participants on routes with longer approach segments and on 90° angle trials, and for passive participants on routes with shorter approach segments and on 120° angle trials. Active participants treated all internal angles as 90° angles. 

Participants performed with lower overall accuracy when optic flow information was disrupted, through the intermittent presentation of self-motion on the small-screen display, in a sequence of static snapshots of the route. Performance was particularly impaired on routes with a long approach segment, but quite accurate on those with a short approach segment. Consistent overestimation of the final angle was observed, and error decreased with increasing size of the internal angle. Participants treated all internal angles as 120° angles.    

The level of available visual information did not greatly affect estimates, in general. The degree of curvature on the roundabout mainly influenced estimates by female participants in the Passive condition. Compared with males, females performed less accurately in the driving simulator, and with reduced optic flow cues; but more accurately with the small-screen display on layouts with a short approach segment, and when they had active control of the self-motion.

The virtual environments evoked a sense of presence, but this had no effect on task performance, in general. The environments could be used for training navigational skills where high precision is not required.

year: 2012

title: Constructing CoRes—a Strategy for building PCK in pre-service science teacher education

authors: Hume, Anne Christine

subjects: Content Representations (CoRes)

abstract: This paper presents findings from an exploratory study into a science teacher education initiative that seeks to build the foundations on which novice teachers can begin developing their pedagogical content knowledge (PCK). The initiative involved the use of Content Representations (CoRes), which were originally developed as part of a strategy for exploring and gaining insights into the PCK of expert science teachers. As the student teachers explored existing CoRes the course lecturer saw potential for more effectively developing their PCK through engaging them in constructing their own CoRes for new topics. When given the opportunity, student teachers found the task challenging and their lack of classroom experience and experimentation proved to be a limiting factor. However, the contribution such a task could make to their future PCK development remained a distinct possibility in the lecturer’s view. In the following year she carefully scaffolded the learning prior to CoRe construction such that the student teachers could more readily access relevant knowledge when attempting such a task. Their resultant CoRes and comments indicate that with appropriate and timely scaffolding the process of CoRe construction does have the potential for PCK development for novice teachers.

text: Constructing CoRes—a Strategy for building PCK in pre-service science teacher education This paper presents findings from an exploratory study into a science teacher education initiative that seeks to build the foundations on which novice teachers can begin developing their pedagogical content knowledge (PCK). The initiative involved the use of Content Representations (CoRes), which were originally developed as part of a strategy for exploring and gaining insights into the PCK of expert science teachers. As the student teachers explored existing CoRes the course lecturer saw potential for more effectively developing their PCK through engaging them in constructing their own CoRes for new topics. When given the opportunity, student teachers found the task challenging and their lack of classroom experience and experimentation proved to be a limiting factor. However, the contribution such a task could make to their future PCK development remained a distinct possibility in the lecturer’s view. In the following year she carefully scaffolded the learning prior to CoRe construction such that the student teachers could more readily access relevant knowledge when attempting such a task. Their resultant CoRes and comments indicate that with appropriate and timely scaffolding the process of CoRe construction does have the potential for PCK development for novice teachers.

year: 2011

title: Interpreting & practicing kaupapa Māori research in a community setting: The in’s and out’s

authors: Thompson, Keri

subjects: Māori

abstract: Pou Tuia Rangahau is a unique community based research unit based within a kaupapa Māori organisation. Kaupapa Māori methodologies are utilised, with the importance of these methodologies being that Māori are defining the process, doing the research for and about Māori, with the eventual outcome being meaningful to Māori. This paper is placed within this wider context of Kaupapa Māori and how it applies to the practice of research in particular. We discuss how we interpret and practice Kaupapa Māori Research (KMR) within an urban community based organisation by highlighting a particular piece of research that was undertaken by Pou Tuia Rangahau, the Research Unit of Te Runanga O Kirikiriroa Trust Inc.

text: Interpreting & practicing kaupapa Māori research in a community setting: The in’s and out’s Pou Tuia Rangahau is a unique community based research unit based within a kaupapa Māori organisation. Kaupapa Māori methodologies are utilised, with the importance of these methodologies being that Māori are defining the process, doing the research for and about Māori, with the eventual outcome being meaningful to Māori. This paper is placed within this wider context of Kaupapa Māori and how it applies to the practice of research in particular. We discuss how we interpret and practice Kaupapa Māori Research (KMR) within an urban community based organisation by highlighting a particular piece of research that was undertaken by Pou Tuia Rangahau, the Research Unit of Te Runanga O Kirikiriroa Trust Inc.

year: 2008