Transcript PPS
The Implications of a City`s layout's Visibility on Wayfinding Performance (preliminary study) Itzhak Omer and Ran Goldblatt Tel Aviv University, Israel ICA Workshop on Geospatial Analysis and Modeling 8 July 2006, Vienna, Austria Background: • A city`s layout's visibility can be defined as the number and structure of visual fields and their integration. • The visual integration of a city`s layout has the potential to effect the quality of spatial knowledge acquired by human subjects while navigating through the city and their ability to construct a cognitive spatial representation of it. • Previous research, especially from the Space Syntax theory, focuses on the effect of one property of visual integration: the topological depth between visual fields (connectivity, integration and intelligibility between the axial lines) and less on the overlapping between them The aim of the research: Examine how the overlapping between visual fields affects wayfinding performance in a 3D virtual city. more specifically: the aim is to examine how the overlapping between visual fields affects the ability to acquire (ordinal) procedural spatial knowledge through direct experience (primary learning) and apply this knowledge in given wayfinding tasks. This examination has been done with respect to the topological depth between the visual fields. Methodology: a 3D Virtual Environment (VE) of an imaginary small scale urban area of about 0.25 Square Km was built using Skyline® 4.6 software Seven landmark elements with unique typical textures were used in the experiment Phase one: A learning phase Participants were asked to observe a recorded `tour` around the city The route never went through the shortest path between any two examined landmark elements: Legend: 1- Clinic 2- Commercial center 3- Tree 4- School 5- Historic building 6- Restaurant 7- Square A sketch map examination: Participants were asked to mark on an anchored map the exact location of the seven city’s elements. This allowed us to examine the quality of the participant's configural spatial knowledge. start square tree The map on which participants were asked to mark the exact location of the elements for revealing level of configurational knowledge Phase two: A wayfinding task phase Five wayfinding tasks were given to participants. They were chosen with respect to the overlapping between the visual fields and with respect to the topological depth between them. Task Origin Target Common visible elements Length of the visual chain 1. (ST) School Tree 1 1 (square) 2. (RS) Restaurant School 2 1 (historic building or square) 3. (HS) Historic building Square 3 1 (school or restaurant) 4. (HC) Historic building Commercial center 0 5. (CC) Clinic Commercial center 0 3 (restaurant and square and tree) 2 (square and tree) Analysis and documentation: Evaluation of success: 1. Length of route: 2. Mean distance error: We estimated ease of task completion using the length of the taken route during the wayfinding task relative to the shortest available path Example (one task): we calculated for each participant the mean distance error of the elements` location on the map he/she drown in relation to their real location Example (one participant): A A = shortest paths = taken route A = real location A = estimated location = distance Results 1. The effect of the visual integration on procedural (ordinal) knowledge 100% 90% 93% 80% 70% 60% 71% 50% 57% 40% 30% RS ST HS restaurant - school school - tree historic building - square (2 common elements) (1 common element) (3 common elements) 20% 10% 0% 90% 80% 70% 75% 60% 50% 40% 57% 30% 20% HC CC 10% 0% historic building - commercial center clinic - commercial center (3 steps) (2 steps) 2. The effect of visual integration on configurational knowledge Success rate during wayfinding task Examination of the relation between the performance of the participants was found to be correlated (R2=0.82) with the accuracy of the landmark locations on the maps drawn by the participants at the beginning of the wayfinding task phase. 100% 90% 80% 70% 60% 50% 40% 30% 20% R2 = 0.8152 10% 0% 2 2.5 3 3.5 4 4.5 Mean distance error on map 5 5.5 6 preliminary Conclusion and further research 1. A high degree of overlapping between visual fields and a short topological depth between them contribute to the acquisition of a more accurate procedural and configurational knowledge. 2. The results of the research encourage the use of complementarily methods for analyzing the City`s layout's Visibility which takes into consideration the overlapping between visual fields in addition to the topological depth between them. A multidimensional topological analysis is an example for such kind of a method.