In this position paper, we create an outlook over the landscape metaphor as a tool help in data analyst tasks. As we are intuitively able to gauge the natural landscape, a metaphor can help to understand the data landscape. In this work, we present the meaning of metaphor-driven design, the essence of the concept "landscape" and discuss ways to interact with such a data environment. Finally, we suggest tools for orientation and operation tasks in a virtual landscape. CCS Concepts: • Human-centered computing → Virtual reality; Interface design prototyping; Information visualization;
The use of metaphors as a means of designing interactive systems is based on the idea that abstract structures
in information technology do not have a "natural" shape. Data structures consist of relations, dependencies or
proportions. With regard to the underlying arrangement and organization of elements, an "image" is not yet
required. But only through an image, data structures become visible, navigable, memorable and manipulable.
To solve this problem, we developed the method of metaphor production [
Basically, the method serves to design interaction metaphors for closed systems (e.g., the control system of a production unit). Such a system becomes understandable and usable. Suitable 3D widgets, forms of touch interaction or even Tangibles can now be designed.
In today’s world of Big Data and the challenges it poses, visual analysis and visual data mining in complex 3D visualizations of multidimensional data is one field where metaphors are helpful. Data is mostly visualized by a reduced dimensional representation, i.e. coded by glyphs, color, numbers, or reduced to positions in two dimensions (see Fig 1). The variety of visualization forms illustrates that this complexity is dificult to master, especially with the traditional two dimensional or planar projection. A main problem is that the user with his experience based on practical life and bodily movements remains ’outside’. The lack of immersion, the deep mental involvement, creates a threshold.
Head-Mounted-Displays (HMDs) provide tools to address this problem. The visualizations are immersive, stereoscopic and virtually linked to the movement of the user. Furthermore, dynamic images that always follow the viewing direction do not have perspective distortions. To make use of the metaphorical idea for the visually supported exploration, we recommend metaphors which are related to the "earthly" movements and experiences of the user, for instance a "house", a "theater", a "sports arena", a "settlement" or in case of this work, a "landscape".
VisBIA 2018 – Workshop on Visual Interfaces for Big Data Environments in Industrial Applications. Co-located with AVI 2018 – International Conference on Advanced Visual Interfaces, Resort Riva del Sole, Castiglione della Pescaia, Grosseto (Italy), 29 May 2018 © 2018 Copyright held by the owner/author(s).
Data itself comes in vast amounts and in multivariate and multidimensional form. To demonstrate the complex
facettes of data, Borgo proposes glyphs in [
Visual analytics proposes visual data exploration techniques to divide the labor of handling the data between
human and computer. Keim [
Lakof and Johnson say in [
The landscape as metaphor has been used in related work. Gansner put recommender systems on a map in [
Jerald writes in [
People feel uncomfortable in an open and empty environment. They need some kind of reinsurance to not feel
lost [
This works well with images as data points. When the user has to handle shapeless multivariate and multidimensional data sets, it gets complicated to apprehend data and understand its context. The task of browsing, comparing and exploring data gets harder if it is only reduced to two or three dimensions. Each data point should have its own unique form, which is generated from its own properties. Here we propose glyphs to present multiple dimensions of data in one form. The data gets distinguishable and comparable. Furthermore, it can also provide properties of a landmark, if there are multiple equally shaped or colored data points (see Fig 1). Together the glyphs create a landscape of forms and colors.
The usage of the landscape metaphor requires the consideration of some universal features. A landscape is (1) infinite (not limited), (2) disordered (not orthogonal aligned or screened), (3) natural (not equipped with human paths or social networks), (4) raw (not enriched by grids, contour lines or distance indices), (5) non-directional (not north-oriented).
Looking at complex data visualizations, they have similar properties. Boundaries, geometric abstraction, paths, patterns of visual item, landmarks, line systems, and a compass help to make use of a landscape - in reality as well as on a map. In the same way, virtual landscapes made of data items should be enriched and humanized. Nature has to be transformed into culture.
In addition to the above-mentioned features, another very human characteristic must be added: A landscape is (6) invisible (not adjusted to the human perspective)
This applies in particular for a virtual landscape that is visualized in an HMD. The landscape must be perceived from a human eye level, with a human opening angle and up to a plausible distance. Only then it fits human experience. The horizon is oriented orthogonal to gravity and separates the top from the bottom. The efects of near and far range perception should also be considered. The possibility to shift the field of view of the HMD slightly to notice visual displacements of landscape parts helps understanding the arrangement of data items. Utilizing the motion parallax of immersive systems is an option to recognize outliers or anomalies in data sets. 52 •
When we talk about a landscape for orientation, there is no way to ignore the interaction techniques and
principles of navigation. Jerald defines the goal of navigation as "determining and maintaining a course of
trajectory to an intended location" [
Wayfinding requires certain skills like identifying the own position, creating a cognitive map of the environment
or planning the next steps to the target. Landmarks or other unique cues in the world can help to perform this
process. They are the first points of reference when the user enters a scene. The hints can be subtle or obvious,
which is both necessary to find the correct way [
Travel describes the active or passive movement from one location to another. It can be done in various forms,
e.g. walking, driving, flying. In some cases, the user will not have any choice at all (like in a movie or simulation),
where in others he alone decides were he wants to travel. When people actively move, they rely on the optical
lfow and the egocentric direction. Optical Flow is "the pattern of visual motion on the retina [...] caused by the
relative motion between a person and the scene" [
It should also be considered that the user can use two fundamentally diferent forms of interaction. On the
one hand, he has an influence over the perspective of the image through his limited bodily movements. On the
other hand, the use of Controllers helps exploiting the possibilities of the virtual world. This transition should be
noticeable. The user is able to utilize the parallax efect with a lateral movement of the head in one moment. Then
he can suddenly shrink the patterned landscape to a small knot and view it from all sides. This example shows
the existence of two main types of metaphors: Orientation Metaphors and Operation Metaphors [
Orientation Metaphors describe ideas how users can deal with spatial orientation [
Due to the major importance of landmarks the use of some striking cues in a data item landscape should be considered. Those could be special peaks or towers that will be added to the data landscape manually. They do not necessarily have to have something in common with the data items at all. But it is also imaginable that data items are mapped in such a way that striking structures will provide visual cues that can serve as landmarks. Glyphs which have similar forms or positions may create a pattern which could serve as a landmark.
To distinguish separate areas, regions should be noticeable diferent. In real urban landscapes, building styles, colors and lights can do this task. In our case, assorted characteristics of data items like size or color help to highlight separate regions. For far distance perception, properties with high contrast should be used. As an additional help, edges are suitable to mark boundaries between regions. Possible counterparts in a real environment would be rivers, lakes or fences.
In order to simplify traveling in virtual data environments, the landscape can be enriched with paths. The segments between two locations will serve as prescribed direction when the user is walking. Furthermore, they will act as landmarks, if the user views the landscape with a bird’s-eye view. How cues are perceived is context-driven. In conjunction with paths, knots and intersections are central orientation points. They can also be enriched with signs that point the way to a specific property or value.
A more artificial approach is the use of grids, patterns or contour lines. Like on a map, data landscapes can be enriched by descriptions, signs and especially reference systems that provide additional information. It is possible to add other semantic layers through color overlays or relation as in a graph visualization (see Fig.4).
The following list gives an overview of the mentioned orientation tools and some advantages and disadvantages.
+ spatial orientation is significantly improved + great control of position and form of landmarks O only used for orientation purpose − artificial landmarks may distract from data items − adding requires additional manual work
+ spatial orientation is improved + no manual extra work − data mapping must cover two tasks: information visualization and landmark establishment − very limited control of position and form of landmarks 54 •
+ clear distinction of areas through style or color attributes + can be done automatically by data mapping algorithms O regions classification depends on data mapping or must be done manually O artificial cues like borders or fences are possible, ...
− ... but may detract from the data items Paths + cues for walking directions help users to travel + network of paths forms intersections and knots + knots can be enriched with signs + from above, paths can serve as landmarks − heavy manual workload during development − path creation requires specialized experience
+ reference systems that provide spatial information + can be enriched by descriptions, annotations, signs + further semantic layers can be added O more artificial approach − additional workload and experience required
Unlike in reality, the user has the freedom to scale and move any objects. Due to the level of freedom, adverse efects like lost-in-space or motion sickness can appear in virtual reality. However, the mentioned enrichment of the landscape creates the standards and reference systems that the user needs to evaluate his manipulations. In addition to usual methods for data handling, like filtering and sorting, we propose a more direct way. The user should modify, form and shape the presentation of the data world with his hands (or controllers) in a natural way. Thus, he becomes a craftsmen of his own vision.
To work with the landscape and thus with the data representation as glyphs the user needs interaction tools. The spectrum ranges from tools users would also use in a real landscape, e.g. a compass, to virtual tools for manipulation of the environment in a fanciful manner, e.g. shrinking mechanisms.
Before the user is able to manipulate the virtual data environment, a reasonable decision should be made, what objects and areas are part of the selection. Therefore, a selection tool is recommended. When the user walks through the landscape, he could just point with his hands or controllers towards a point of interest. Bigger areas could be encircled. This ray-cast-like option ofers a fast but inaccurate selection performance. Even if the aiming ifeld is adjustable in size and shape, the selection of data items which are far away will be quite dificult. Shifting perspectives to bird’s-eye-view or similar options can help to specify the interaction. In some situations it is necessary to shrink the whole landscape to a manageable size to get an overall picture before further selection can be done. The same efect would be achieved with a zoom but considering the virtual possibilities it seems the more transparent option to let the user hold the landscape in his hands and form it to his own liking. The usage of multi-selection and grouping methods should also be considered.
Like mentioned before, shrinking the data world is an important manipulation opportunity. To achieve a solid handling of the virtual landscape, miniature tools for translation, rotation and scale tasks are suggested.
Examples are related 3D-gestures like turning and stretching. Despite landmarks and other cues, they prevent the loss of orientation, a virtual compass and a function for north-orientation of the landscape can also help. The comparison of diferent height levels in the data is another interesting task. Where are hills, where are valleys? A flooding-tool could be used to fill the landscape with a virtual fluid. An alternative is a section plane, which grants comparability.
For navigation, the possible methods range from walking to teleport. For exploration tasks of small group
of data items, walking techniques are the best choice, where larger areas require flying- or floating techniques.
The mentioned teleport-method should only be used for small distances because the risk of losing orientation is
too high. Another way to facilitate the user movements are rotational and transitional gains as they will aid in
exploring large virtual environments [
An overview of the mentioned operation tools including advantages and disadvantages can be found in the list below.
+ tool to prevent orientation loss + automatic north-orientation is possible O operation has to be learned
+ height overview and comparison of diferent levels + cutting intersection plane can reveal hidden data items − flooded area may covers relevant data underneath
+ user holds the world in his hands and adjust it as needed + exploration enables an overview + details can be shown on demand with scale/zoom − easy to loose orientation − operation is challenging and has to be learned
+ user can use motion parallax to compare data items + patterns are easily recognized through shifting movement + rotational and transitional gains are applicable, which can help users to navigate through large environments and reduce exhaustion − disorientation and motion sickness may occur with gains
+ diferent navigation techniques possible, depending on the application + walking for deep exploration and detail browsing + flying/floating for fast overview O teleport to pass gaps or longer walking distances − walking: often too slow to explore whole data set − flying: continuous flow can be too fast for details 56 • 4
The idea of a landscape metaphor for glyph-based big data visualizations is a novel approach to make large volumes of data graspable for users. As we are intuitively able to appropriate and understand the circumstances of a natural landscape, we can also overview the data landscape. In this paper we present the means of metaphordriven design, the landscape concept and discussed ways to interact with such a data environment. Finally, we suggest tools for orientation and operation tasks in connection with this topic.
Because this is a presentation of ideas and concepts, we can’t ofer evaluated conclusions. It should be examined whether the theoretical ideas work as expected. Therefore, user studies are considered. It is to be expected that the landscape metaphor will not fit every use case. Another task is hence the examination of diferent examples and data sets. For now, we did not cover the topic of mapping data items characteristics to features of the landscape. The variety of possibilities is enormous and will be included in future work.
Apart from this, the approach encourages the application of other metaphors like urban structures, cities or
on a larger scale cosmic formations. For example, learning from architects and city planers [