how much interactivity does the public want? an assessment ... · an assessment of interactive...

How Much Interactivity does the Public Want? An Assessment of Interactive Features in Virtual Landscapes

Olaf SCHROTH and Willy A. SCHMID

1 Introduction

Landscape visualization is a strongly technology-driven field with all its implications, i.e. the rapid development of new applications which makes it difficult to keep pace with the theoretic basis. Although an increasing amount of literature addresses methodological issues of landscape visualization and related fields like geovisualization, there is still a lack of profound knowledge and WOOD ET AL. (2005: 305) indicate the danger of technology-driven „ad hoc applications“. Therefore, further practice-oriented research is necessary to evaluate the benefits and limitations of geovisualization in various fields. Landscape visualization can draw on other disciplines for an interdisciplinary approach, e.g. computer visualization, human-computer interaction and cartography. From a cartographic point of view, usage conditions and user profiles determine map design and equally the design of visualizations. In literature, various models describe the context in which maps are used and it is likely that some of these approaches and ideas can be transferred to the use of virtual landscapes as well. A key idea is the description of usage environment and user profile, i.e. who is using the visualizations and in which context (DRANSCH 1997)? In this paper, the use of interactive landscape visualizations as a tool in participatory planning is under research and it is asked for the technical requirements that result from this special usage environment.

1.1 Usage Environment: Participatory Planning In order to describe the usage environment, a closer look at participatory techniques is required. First of all, attention should be paid to different levels of participation. Based on ARNSTEIN´s (1971) ladder of participation, several authors have defined classifications of different levels of participation. According to ARNSTEIN, real participation involves the cooperative sharing of power, i.e. in form of partnership, delegated power or citizen control. In contrast, attempts to manipulate the public opinion cannot be regarded as participation at all. Today’s classifications of participation largely include levels of information, consultation, advice and really collaborative production and decision of plans. It has been argued that a higher level of involvement also requires more interaction between the participants and hence, more interactive tools (VAN LAMMEREN & HOOGERWERF 2003, LANGE ET AL. 2003). The main arguments for participation have been that participation will increase the legitimisation of planning decisions and that participative planning processes result in a higher quality of the outcome and a stronger support of the outcomes likewise. It has been suggested that interactive visualizations might further contribute to the quality of

O. Schroth and Willy A. Schmid

participative processes and previous publications explored the potential of the tools by empirical qualitative methods. However, it should be noted that challenges in participation changed over the years. While the main challenge during the 1970s and following decades was to include the public in government decisions, public participation is wide-spread in western industrial countries today. Nevertheless, SELLE (2005) observes an internal and external corrosion of participation, e.g. through participation without any real impact, through functionalisation and populistic use of participation. Then, government is not the mighty counter-part anymore but there is a confusing variety of private and public stakeholders involved in planning decisions and conflicts rise between their interests. Is there any contribution that interactive planning tools may provide in such a fragmented context?

1.2 User Profiles: Diverse Interests Referring to the concept of usage environment and user profiles, the previously described needs of planning participation can be expressed by: • Participation is inherently a collaborative process, involving a group of people who

interact with the visualizations. • Because participation is an open process, the group of participants may be very

heterogeneous with different interests and different skills in map reading, in the planning topic etc.

In most participatory settings, two key groups, i.e. experts or planning professionals (planners, surveyors, architects etc.) and community members are involved. Still, the label “expert” needs a more detailed description, because this paper also addresses experts in the sense of people with advanced skills in map reading and with experience on 3D visualizations. Due to their education, architects, geographers and planners may be experts in this field, but there are also local people with comparable skills.

1.3 Interactive Functions Virtual landscapes are characterised by different kinds of representation (level of realism, scale, perspective etc.) and by different forms of interaction (navigation, interaction with the data etc.). In this context, interaction can be defined as a series of goal-oriented actions that are determined by the interaction between human and computer (FUHRMANN 2001, ISSING & KLIMSA 1997). Today, the producers of geovisualization not only work with variables like colour, size etc. but the choice and design of interactive functions becomes part of the visualization process as well. Especially realtime rendering techniques introduced various possibilities because they make it possible to explore a landscape in its full scope and to navigate through temporal and dynamic data. Therefore, “interpretations of the represented phenomena and the consequent understanding are now a combined function of symbolization and the facility to interact with the representation” (EDSALL & SIDNEY 2005: 580).

An assessment of interactive features in virtual landscapes

Although the theoretic foundation for virtual landscapes does not keep pace with the fast technological development yet, there are classifications of dynamics and interactivity, evolving from fields like landscape visualization, computer visualization and cartography. In the context of forestry, SHEPPARD (2004) classifies different “presentation formats” of landscape visualizations by the degree of dynamism, i.e. static images, immersive static imagery, limited animation, pre-pared animation paths, animated conditions and real-time interactivity. In cartography, the development of interactive atlases provides experiences on various interactive functions. Based on a literature review and the experiences with the Swiss multimedia atlas, HURNI (2005) identifies nine groups of functions for cartographic applications and most of these may be transferred to the description of virtual landscapes. A key group deals with navigation, including geographic, thematic and temporal navigation. In addition, Hurni defines groups of map functions (layers, overlays, data exploration etc.), database-, atlas-, didactic, cartographic and map usage functions. Other functions may include multimedia features and GIS analyses.

1.4 Qualitative Assessment of Interactive Visualization Tools From this broad range of interactive map functions, a number of features was transferred to 3D, implemented for the UNESCO Biosphere Reserve in Switzerland as case study site, and evaluated in different stages of participatory processes as part of the EU project VisuLands. In summary, the interactive construction of spatial settings made it easier to highlight spatial phenomena and analyses functions provided powerful instruments to illustrate key driving forces. During the process of goal definition, the overlay of different interests by competing stakeholders finally lead to a consensus. Furthermore, people asked for the inclusion of additional context information, e.g. statistical data or indicator data, for a more objective assessment of the 3D visualizations. Above all, interactive navigation was necessary to provide the navigator with the necessary flexibility to react to the needs by participants and moderator. Nevertheless, it should be noted that the use of the tools was sometimes limited, because requested data had to be prepared first, interactions took too long to keep pace with the discussion or technology was too complex for the work in small groups. For a more detailed description of the outcomes of the qualitative research part, please refer to the paper by SCHROTH (2005) in last year's Anhalt conference proceedings.

2. Quantitative Assessment of Interactive Visualization Tools by the Public

2.1 Method The following quantitative questionnaire resumes and complements the previous explorative study, both part of the VisuLands project. Among the six European project partners, the questionnaire was complemented in the British and Swiss case study sites. It started with a presentation of 2D maps, 3D visualization types and interactive features as “stimulus”. The interactions were controlled by the research team, not the participants, so that everybody saw the same set of interactions. Afterwards, questions were asked on the


participant’s perception of the maps and the 3D visualizations, their assessment of the 3D visualizations, their involvement in planning participation and the project, and socio-demographic data on their background. In addition to the closed multiple choice questions and rankings, the questionnaire contained several open questions to allow qualitative feedback, too. Furthermore, the reactions to the presentation were documented on video if possible. In the British (Clashindarroch, Scotland) and the Swiss study site (UNESCO Biosphere Reserve Entlebuch, canton Lucerne), the questionnaires were conducted at two occasions, first at a local exhibition and later, with a school class. For each case study site, the visualization types and interactive techniques were implemented in local models. This “localisation” of the visualizations was necessary to test whether people can orientate in the models and to discuss local planning issues. However, the localisation may also limit the comparability of the study site results, although a strict presentation template and standardised visualization types were given. The following analysis mainly refers to question eight in part B of the questionnaire, which addressed different interactive functions: Earlier you were shown various features of computer visualizations. Please rank the features in order of importance to you if you were involved in making a comment on landscape proposals.

Fig. 1: English version of the ranking on interactive features

The question is formulated as a ranking that means the respondents have to decide on the order of the various interactive features. In comparison to rating scales, items in ranking questions usually receive a lower assessment, because respondents have to balance their decision against alternatives and they cannot assign a high rating to all items.

1. Walk-through movement 2. Viewing different options 3. Time travel 4. Photo-realistic images 5. Inclusion of non-visual information


Classification Questionnaire

Geographic Navigation

Walk-through

Temporal Navigation Time travel

Scenario Navigation Viewing Options

Context Information Non-visual information

Fig. 2: Screenshots from the interactive features that were used as stimulus to the quantitative questionnaire

Additionally to the features, shown in the table above, photorealism is listed in the questionnaire. Actually, there are important interactive features that allow the user to choose the representation and its level of realism, but these functions were not exemplified during the stimulus presentation. For that reason, “photorealism” is not analysed in detail during the following chapters, although its rankings are listed, because the rankings of the other items depend on it.


2.2 Participants In the socio-demographic part of the questionnaire, gender, age, education, place of residence and profession were recorded. On basis of these data, respondents are classified with regard to landscape related professions (experts and lay people), age groups (school age and adults), and map reading competence (experts and lay people) for the British and the Swiss study sites. It should be noted that the low number of experts in the sample limits the statistical power of statistical tests on group differences. Therefore, the Swiss and British samples are merged for a comparison of professions, although the stimulus was not exactly the same for both groups due to the localisation of the images. Any questionnaires that were not filled in correctly, are not considered in the analysis.

2.3 Assessment of interactive features by participating groups In contrast to the previous qualitative study on the benefits of interactive tools, the questionnaire results reflect the direct assessment of the interactive tools by the users. The first table shows the ranking order in percentages for the combined sample of both sides together. Then, the mean rankings are given for the combined sample and for the Swiss site only, however, both result in the same ranking order. This ranking order is weighted (ranking place one gives five points, place two gives four points etc.) and illustrated as a bar chart:

Table 1: Ranking order in percentage for the Swiss and the British sites in one sample

Ranking Interactive Feature

1 2 3 4 5

Walk-through 16.9% 15.4% 19.9% 27.2 20.6%

Viewing options 23.5% 28.7% 27.2% 13.2% 7.4%

Time travel 27.2% 26.5% 22.8% 19.1% 4.4%

Photo-realistic 26.5% 23.5% 23.5% 16.9% 9.6%

Non-visual 2.2% 5.9% 11.0% 22.8% 58.1%


Table 2: Mean rankings for the Swiss and the British sites in one sample

Min Max Mean Std. Deviation Time travel 1 5 2.47 1.205 Viewing options 1 5 2.52 1.199 Photo-realistic 1 5 2.60 1.302 Walk-through 1 5 3.19 1.380 Non-visual 1 5 4.29 1.025 Valid n = 136 (from 167)

Table 3: Mean rankings for the Swiss site only

Min Max Mean Std. Deviation Time travel 1 5 2.23 1.171 Viewing options 1 5 2.77 1.154 Photo-realistic 1 5 2.83 1.503 Walk-through 1 5 3.15 1.460 Non-visual 1 5 4.00 1.225 Valid n = 53 (from 60)

Fig. 3: Ranking for the Swiss sample (the aggregated sample of both sites results in the same order)

Apparently, the standard deviation shows that the distribution is not wide, so the rankings were rather homogeneous with few outliers. Overall, time travel, i.e. the animation of landscape change over time, received the highest ranking which matches with the comments from qualitative documentation: “At a glance, I was able to imagine how the change will take place” (questionnaire participant, translated from German).

0

1

2

3

4

Ranking(1- 4 points)

Time travel Walk-throughViewingoptions

Photo-realistic

Non-visual


Then, viewing options or scenario navigation, received the second highest rating. It should be noted that the scenario method is commonly used in participatory processes and together with 3D visualizations, it is a very promising combination. Furthermore, planning decisions often include polls on alternative scenarios in either way and the ranking gives evidence that such decisions will benefit from interactive visualizations. In comparison to time travel and viewing options, the walk-through option, or in other words realtime navigation, received only an average ranking, although it proved to be very important in the qualitative pre-study. However, a closer look at the workshop documentations shows that realtime navigation was mainly used by the navigator to show specific views, but the movement in-between was rarely shown, because it could distract from key issues. Another possible explanation, which is examined in section 2.4, is that walk-throughs are more demanding for users and that the low ranking goes back to the average low 3D experience of the people in the sample. Finally, the inclusion of non-visual information, e.g. diagrams of indicator data, received a surprisingly low rating. If the interviews from the explorative pre-study are included, the results are even more surprising, because during the workshops many participants explicitly had asked for such an option. That the final combination of non-visual information and 3d models did not receive a better assessment then, may have various reasons: Either the design of the visualizations was not optimal yet, or the indicators were not relevant, or it is too much information in one, to combine virtual landscapes and non-visual information in one interface. Here, further design proposals for a successful combination and further evaluations will be necessary. First of all, it is examined whether experts from landscape related disciplines ranked it higher than the average.

2.4 Group differences The previously raised questions may be answered, if the data are analysed on group differences. Especially for the walk-through and the inclusion of non-visual information, it is very interesting whether these items received a generally low rating or whether they were ranked differently by experts and lay people. Unfortunately, the number of expert participants was not high enough to provide evidence that is statistically significant, but at least, the analysis shows some trends.


Experience with 3D visualizations

Table 4: Mean Rankings by users with experience in 3D (combined sample)

Min Max Mean Std. Deviation Viewing options

1 4 2.19 1.001

Time travel 1 5 2.48 1.341 Photo-realistic 1 5 2.74 1.318 Walk-through 1 5 3.48 1.087 Non-visual 1 5 4.30 1.103 Valid n =27 (from 28) Respondents, who indicated sufficient experience in 3D visualizations, seem to rank similarly to the general, less experienced, sample. Although it might have been assumed that experienced visualization users are more used to walk-throughs, there is no evidence that they will rank them higher.

Profession

Table 5: Mean Rankings by experts in landscape related disciplines

Min Max Mean Std. Deviation Photo-realistic 1 5 2.20 1.373 Viewing options

1 4 2.27 .884

Time travel 1 4 2.73 1.100 Walk-through 1 5 3.53 1.302 Non-visual 1 5 4.07 1.335 Valid n = 15 (from 17) While both groups, experts and lay people, more or less agree in their high assessment of viewing options and the very low assessment of non-visual data inclusion, there are differences in walk-through and time travel. It seems that “landscape experts” are less enthusiastic about the benefits of time travel and even more sceptical about walk-throughs. It could be suspected that the experts do not think that the perception of movement through the landscape will be relevant for planning decisions. For the time travel option, it may also be possible that expert do not trust in the representation of landscape change over time. On the contrary, in the focus group discussions from the explorative study the presented animations over time were mainly approved. However, it seems a bit surprising that the landscape experts also rank the inclusion of non-visual data rather low.


Age It is a wide-spread assumption that young people, Petschek (2005) calls them “generation Playstation”, will assess landscape visualizations differently to older generations, because they are more used to such images and tools. Actually, the numbers show some variations from the means of the general sample, but are they statistically significant? A T-Test (normal distribution is given) verifies that the lower ranking for the viewing options feature does significantly differ from the results of the basic sample.

Table 6: Mean rankings by participants under 20 years

Min Max Mean Std. Deviation Time travel 1 5 2.23 1.130 Photo-realistic 1 5 2.63 1.215 Walk-through 1 5 2.98 1.520 Viewing options

1 5 3.05 1.234

Non-visual 1 5 4.14 1.060 Valid n = 43 (from 45) It is not clear, why this age group ranks viewing options lower, and the qualitative comments do not provide additional interpretations either. It could be speculated that they ranked it lower because these respondents lack any experience in actual planning processes while many of the adult visitors are involved in workshops, forums or at least polls on planning issues. Alternatively, it could be possible that the shown options did not meet the high expectations of the young users, who are used to very sophisticated 3D visualizations from the media. It is also possible that the ranking of viewing options was displaced by the walk-through, which got a slightly higher response than in other groups.

3 Discussion

Most evident, tools that follow a time travel metaphor and include landscape dynamics and landscape change over time, are ranked rather high by all groups. It should be discussed whether such tools will contribute to a more process-oriented perception of planning in contrast to traditional “blueprint plans” that address a static future state. In this context, time travel may further provide as a very helpful tool which is well acknowledged. The provision of scenario alternatives with the possibility to navigate through them is also acknowledged by most users and confirms that visualization tools are an appropriate support of the scenario method. Although the scenario method traditionally focussed on written scenarios, the use of maps (Stiens 1998) and of photo-manipulated images (Tress and Tress 2003) already proved successful. With regard to today’s techniques and the results from this questionnaire, an enhanced use of 3D visualization tools seems promising. The group of young users is an exception, because they ranked the viewing of options


significantly lower than other groups, giving photo-realism and walk-through a slightly higher ranking in exchange. It was explained in the qualitative pre-study that realtime navigation is crucial to provide at least some of the flexibility that is necessary for the use of 3D visualizations in collaborative planning settings. However, the results of the questionnaire suggest that a further use of realtime navigation for walk-throughs is less demanded by the public. The feature still received a middle ranking and it may have its use in specific planning situations, e.g. the planning of a route where the perception of the landscape by walking this route will affect the path-choice decision (Loiterton and Bishop 2005) or as an introduction to planning discussions or exhibitions, where walk-throughs and fly-overs can give a first impression of the area. The most surprising outcome is the low ranking the combination of non-visual information and 3D visualizations received, because such a feature was seen as promising in the previous qualitative interviews and group discussions. Therefore, it is suggested not to cease this line of development but to review the design of non-visual information in 3D environments and the choice of non-visual information. Altogether, temporal and scenario navigation seem to be well acknowledged among the respondents from this sample, and these features do not demand to much technical requirements anymore. In comparison, other forms of interaction seem to be more of specific use and further research is needed to explore in which situation they are really useful.

4 Acknowledgements

This work is part of the VisuLands project in the 5th Framework Program of the European Union. Special thanks go to Prof. Eckart Lange who co-initiated the Swiss project group and to Ulrike Wissen who worked on the project, too. Finally, we would like to thank the Canton Lucerne for providing geodata for the case study site and to Max Hislop and his colleagues at the Forest Research Institute in the United Kingdom, who digitised and summarised the questionnaire data.

5 References

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