The influence of informational aspects on the urban ‘wayfinding’ virtual experience

視覚情報が経路選択に及ぼす影響に関する研究 ―仮想空間上の都市において―

05M43329 André Soares Lopes Adviser Norihiro Nakai

アンドレ・ソアレス・ロペス 指導教員 中井検裕

要約 本研究は、どのような情報が都市内における経路選択に重要な影響を与えるかについて述べ

ている。まず初めに、本研究に関わる重要な概念を定義する。次に、都市の経路選択の容易性

に関する情報の効果を測定する目的で 2 つの調査を行う。1 つ目は経路選択に最も影響を与え

る情報の側面について予備調査を行った。2 つ目はインターネット上で模式的に映像により都

市を作り出し、どのような経路選択をするかを調査した。経路選択においてランドマーク、地

図、標識、見通しのよさが特に影響を与えているという知見を得た。

1. Introduction Background

The term wayfinding is presently understood as being the user’s experience of orientation and navigation, the action of finding paths for a certain destination, especially within the built environment. In a more generic way of defining the term, Kevin Lynch (1960) points out several examples of orientation methods, focal and referential points through out time, space and culture; being those direct reference to how wayfinding evolved with time, as well as tracing links between legibility, memory, and cognition to the process of wayfinding.

Another way to see wayfinding is as “a series of direction choices at decision points” (A. Klippel et al. 2004). While these choices are referenced by external factors other than the commonly said personal “sense of direction”, referential aspects, especially in urban areas, responsible for the formation of individual legibility, become part of the concept of wayfinding.

“It is the cognitive element of navigation…the tactical and strategic parts that guide movement. It is not merely a planning stage that precedes motion. Wayfinding and motion are intimately tied together…” (Darken, 2001). From Weisman’s (1981) words; the variable that

can influence the process of wayfinding inside built environments can be classified in 4 categories; (a) Visual access, or as several other researchers may call it, visual permeability, (b) architectural differentiation, being a fundamental brick for the creation (acceptance) of landmarks, as stated by Lynch (Lynch, 1960) (c) signs and numbered destinations and (d) plan configuration, which refers to the spatial shape.

From this the other important term referred to - information - can be explained. According to Princeton University’s Cognition Science Laboratory, information is “data: a collection of facts from which conclusions may be drawn; "statistical data" or “knowledge acquired through study, experience or instruction”. For the research’s purpose these

definitions would suffice since the information we seek to analyze and possibly measure is that attributed to common daily use.

The main question

Permeability, a major characteristic of space that influences wayfinding experience, different than one might think by reading the existent literature (Moughtin 1992, 1999; Carmona 2003), is not constituted only by size of blocks and choice of routes. In fact, in consistency with the idea that cognitive values (and therefore information) are vital for navigation and wayfinding ease, the existence of a greater number of route choices on an urban setting; although at first suggesting a much higher level of permeability, would in fact create the necessity of a substantial increase in the level of informative infrastructure to keep such environment understandable (legible). Therefore one may say that connectivity (and therefore route choices) by itself is not applicable as an increment on permeability level or wayfinding ease.

What, then, is the consequence of this inverse proportion of value related to two main characteristics of navigation and wayfinding (information as cognitive value and choice of routes as a physical characteristic)? For that matter, this research calls attention to the doubts on the importance of information for the level of permeability on urban settings and wayfinding.

The hypothesis presented here is that informational aid is indispensable for wayfinding ease and higher urban permeability; That is because the characteristics responsible for such permeability level are dependent on external information for coherent direction choices at decision points (wayfinding).

The questions that emerge are; how those informational aspects influence the decision making on urban navegability, how dependent on information are the navigability and wayfinding process to be efficient, and how

people respond to the existence of such informational infrastructure.

2. Proposed Experiments To answer these questions two exercises were

developed. The first one is based on synthetic models, theoretical urban grids, where the experiment takes place, measuring the changes in the chances of a user to reach the destination by following the ‘excellent route’ caused by the influence of informational aspects. The first exercise objective is to determine the most influential informational aspects that will be used on the next experiment.

The second experiment is a photo survey, a measurement of how the informational experiments influence real decision making in urban environments. Two areas, Shimokitazawa and Makuhari, both around Tokyo Metropolitan area, were used as scenario for the experiment, which was applied to 135 users, all non-japanese.

Experiment 01 – The synthetic grids Firstly, three synthetic grids were chosen as stage for the experiment, all of them presenting very different physical characteristics (shape) and path connectivity. From the most simple (orthogonal grid) to the more complex (Chihiro grid (Saito, 2006)) they all are subjected to the same experiment. Pic.01. Two examples of synthetic grid patterns. Urban grid in light gray; (A) Origin; (B) Destination; (Doted line) Area under study and (Full line)

excellent route”. “

Defined an origin and a destination inside the grids, an excellent route is determined by following a set of characteristics which are: I.Shortest way, II.Directness, III.Least number of ‘decision points’ and IV.Least number of changes in orientation. The measurement is calculated as the probabilities of any user to follow the predetermined ‘excellent route’ rather than any other, to reach the destination. In each trial informational aspects are added to the scene and the probabilities measured again. With this procedure we aim to distinguish the informational aspects that most affects the chances of successful navigation.

The measurements occur in every decision point, calculating the chances for the ‘excellent route’ to be chosen,

always related to the origin (cumulative). The informational aspects that were analyzed are:

a No informational aspects b Street name c Orienting signs d Visual permeability e Cardinal points f Landmarks g Maps/Orientation devices

Table 01. Some of these aspects, namely traffic signs, landmarks and street names, while during the measurements were divided in in more than one topic. For example traffic signs would be divided in groups concerning the positioning of the signs inside the area of analysis.

For further confirmation the same exercise was applied on real life environments. For this purpose 2 locations presenting different levels of grid complexity were chosen. The locations are: Makuhari bay town (orthogonal grid), and Shimokitazawa (organic grid).The following numbers were taken from the measurements:

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Pic.03. (Left) Makuhari and Shimokitazawa. (Right) The synthetic grids.

Respectively from the synthetic and real grid’s results, in this first experiment, graphs were drawn for the purpose of comparison. The graphic results (given in percentage) show irrefutable similarities on how the informational aspects affected the navigation probabilities. From this comparison we can point out the 4 most influential informational aspects, which are; landmarks, traffic signs, maps and visual permeability. Let us see now how they affect user’s wayfinding experience in real environments.

Experiment 02 – The Photo survey

No inform

ation

Street nam

e

Street nam

e and n

umber

1 sign (p

)

1 sign (n

)

2 signs

(p)

2 signs

(n)

V. permeabili

ty

Cardinal po

ints

1 Landmark (

o)

1 Landmark (

w)

2 Landmarks

(w)

2 Landmarks

(w)

rientation

device

Makuha ri

S himokit zawa

0,00%

1 00%

2 00%

3 00%

4 00%

5 00%

60 00%

70,00%

80,00%

90,00%

100,00%

Probability

0,

0,

0,

0,

0,

,

No inform

ation

Street nam

e

Street nam

e and n

umber

1 sign (p

)

1 sign (n

)

2 signs

(p)

2 signs

(n)

V. permeabili

ty

Cardinal po

ints

1 Landmark (

o)

1 Landmark (

w)

2 Landmarks

(w)

2 Landmarks

(w)

entation d

evice

Ba sic Grid

He xagon

Chihiro

0,00%

10,00%

20,00%

30,00%

40,00%

50,00%

60,00%

70,00%

80,00%

90,00%

100,00%

Probability

Pic.02. Shimokitazawa(up) and Makuhari Baytown (right). The areasunder study are markedwithin the dotted line.Origin and destinationare respectively locationsA and B. (source: http://maps.google.com)

This experiment was composed to address the elements that were chosen, amongst all the informational aspects presented in the previous experiment as the most influential on what path choice probabilities are concerned. Trying to simulate a real environment navigation experience, it was used a computer based photo survey. According to Zacharias (2006), choices made based on a series of choices, for both real environment and VR (virtual reality) environment present similar results on the motives and itinerary of users. The user’s objective was to start the survey from a predetermined origin and, by choosing directions at each decision points (street crossings), reach the final destination, which was also predetermined.

The two areas used for the measuring were the same used on the previous synthetic experiment; Makuhari Bay Town and Shimokitazawa.

Concerning the survey, each test, in a total of four, was formed by a series of pages that would display pictures of possible paths one could choose from each decision point, where “pages” would represent street crossings in the real environment. A number of pictures would be displayed representing the various directions possible to be taken from each decision point. By choosing a picture the user would be directed to the next decision point or the next street corner and presented with more choices of paths. Apart from the pictures, the pages would also present to the user a mini map, so that the spatial configuration of each corner surroundings could be better understood.

The experiment was divided in 4 tests; 2 for each area. Each test attempted to measure the influence of one specific aspect on the navigability of the place. The first, on Makuhari Bay Town, attempted to measure the responses related to the existence of visual references (landmarks). In this case the landmark would be represented by the Central Park Towers, located to the north-east of Makuhari (pic 04). In the second test, still in Makuhari, a map of the area would be provided and its influence on wayfinding experience would be measured. The third and fourth tests were located at Shimokitazawa, and the influence of traffic signs was measured this time. From the third experiment to the fourth some images on specific corners were altered (pic 05) to contain traffic signs indicating the correct direction to the predetermined destination users should reach. The data concerning the users who toke part in the survey is as follows, in table 02:

Users data Percentage Total of users 135 people Male 63,70% Female 36,30% Live in Japan 35,56% Know Makuhari 5,19% Know Shimokitazawa 13,33%

Table.02. General information about the users who answered the survey. The survey was web based, distributed on the

internet for invited people. All users were contacted by e-mail and answered the survey at their own homes. Pre

established rules for the survey were controlled by the software provided together with the questionnaire.

Pic.04. Example of how the traffic signs were introduced in thepictures, at Shimokitazawa, for test 4.

Pic.05. In Makuhari the Central park Towers, seen in the pictures

above from two different points inside the area, served as the referencelandmarks to be used for the measurement.

3. Results From the first test, located in Makuhari, we measured the percentage of users who chose the directions represented by pictures in which the destination was visible. For instance the destination users were seeking was the Central Park Towers (pic.05). In the case of high percentage of people choosing the directions (represented by pictures) where the destination was visible would indicate a high level of influence of visual permeability on the wayfinding experience.

Test 01 - Landmark and visual permeability Crossing 3 75% Crossing 11 70%Crossing 4 85,71% Crossing 12 40%Crossing 5 100% Crossing 14 100%Crossing 6 70% Crossing 27 10%Crossing 8 100% Crossing 32 25,35%Crossing 9 100% Crossing 33 56,25%Crossing 10 100% Average percentage 71,70%

Table.05. Percentage of people, from within the total of user who passed by that certain crossing (pic06), who chose directions (represented by pictures) where the destination could be seen.

The results were measured in all street corners from where the destination was visible. These crossings are

represented by numbers (Tab 05; Pic 06) and the results are the percentage of people who chose to follow the pictures containing the image of the destination (Central park towers).

For the second test, a map was added to the test. With this the influence of usage of maps for navigating could be measured. The total accuracy (percentage of users that could reach the destination) was noted being much higher when a map was used during the navigation process.

TEST 01 - Landmark and Visual permeability Total of users who took part in the test 135 How many reached destination 38 Accuracy 28,89% TEST 02 - Navigation with orientation device (map) Total of users who took part in the test 110 How many reached destination 91 Accuracy 82,73%

Table.06. Total accuracy probability from test 01 and test 02.

Pic.06. Makuhari Bay Town (left) and Shimokitazawa (right). Each crossing in the maps is represented by a number. Different kinds of information were considered in each of the areas under research.

For tests 3 and 4 the influence of traffic signs on wayfinding was measured. From one test to the other informative signs were added to 5 crossing (example: pic. 04). The chance for one to follow the direction indicated by the signs was measured through the comparison between test 3, which presented no signs, and test 4, where the traffic signs were added to the scenes. As table 07 shows, the chances of someone following the right direction towards the destination, which are indicated in the signs added to the scene, measured from each isolated crossing (pic.07), and specifically the ones containing signs, is significantly higher then when the same measurement takes place at the same crossings but without the added information (traffic signs).

Test 03 and Test 04 – Result comparison Crossings Test 03 (no info.) Test 04 (signs)04 0,00% 100,00% 13 0,00% 24,00% 19 60,19% 77,45% 44 28,57% 100,00% 45 23,81% 80,00% Average percentage 21,51% 76,29% Total accuracy 21,30% 39,21%

Table 07. Notice that on test 04 (with traffic signs) the chance for a user to follow right direction to the destination is higher than in 03 (with no signs)

It is true that the total accuracy (percentage of users who managed to reach the destination) from test 3 to test 4 (tab.07) do

not show the same kind of improvement as presented from test 1 to 2 (tab.06); but when counted from each crossing where a traffic signs is visible the accuracy level suffers a major improvement (tab 08).

Accuracy measured point by point TEST 03 Accuracy TEST 04 Accuracy Crossing 04 0,00% Crossing 04 33,33% Crossing 13 0,00% Crossing 13 12,50% Crossing 44 57,14% Crossing 44 100,00% Crossing 45 52,38% Crossing 45 100,00%

Table 08. Navigation accuracy (who could reach the destination) measured from each crossing where traffic signs were present.

Population’s samples’ direct accuracy comparison Final results, divided by gender (left), male and female; and by local of residence (right), either Tokyo residents or not.

Males vs. Females

25,88

98,57

23,19

56,92

24,00

55,00

17,95

8,11

0 20 40 60 80 100

Land

mar

kM

apNo

Info

.Si

gns

Total accuracy percentage

Males Females

Residents vs. Non Residents

24,49

80,00

21,05

44,44

31,40

84,29

21,43

36,36

0 20 40 60 80 100

Land

mar

kM

apNo

Info

.Si

gns

Total accuracy in percentage

Residents Non Residents

Experiment comparison

12,5

0,03

100

0,02

12,5

50,0

1

100

0,00

3

25

50,0

3

100

0,00

16,25

50,0

7

100

0,1

12,5

12,5

100

0,02

4

28,8

0

39,2

0

82,7

3

21,0

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Landmark Signs Map No info.

informational aspect

Accu

racy

Basic Grid Hexagon grid Chihiro grid

Makuhari Shimokitazaw a Photo Survey

Experiments’ comparison This graph on the left

represents the direct comparison between the two experiments that took place here; the synthetic test, and the photo survey.

Notice the differences and similarities in the total accuracy levels, related to each of the informational aspects under study.

4. Conclusion From the results presented in here, a direct comparison of numbers is possible, even though definitive statistical proof is not given. The variation in percentage of the population to be affected by the information variable seems big enough to indicate that there is a relationship between information given and the choices made in each decision point during navigation experience. REFERENCES CARMONA, Matthew; et al. (2003) “Public Places, Urban spaces”. Architectural Press, Oxford LYNCH, Kevin. (1960) “The image of the city”. Ed. Martins Fontes, Sao Paulo, 1997 MOMTELLO, D. R. et al. (1999) “ A comparison of methods for estimating directions on egocentric space”. Perception, 28, 981 – 1000 MOUGHTIN, Cliff (1992) “ Urban Design: Street and square”. Architectural Press, Boston, 2003. WEISMAN, J. (1981) “Evaluating architectural legibility: Wayfinding in the built environment”. Environment and behavior, Vol. 13, pp. 189 - 2004