Physical Visualizations: Turning Data into Space

Michael Haley Goldman, United States Holocaust Memorial Museum, USA, Sara Pitcairn, American University, USHMM, USA


As museums continue to explore the visualization of data, can physical manifestations of data sets change our capacity to tell visual stories and increase visitor understanding? Improved access to data as well as changes in technology provide the opportunity to visualize historical data sets as physical spaces in museums that can evoke both historical and felt understanding. Based on examples from several institutions and building on visitor reactions to two recent projects at the US Holocaust Memorial Museum, this paper examines how physical visualizations create a powerful learning environment for the public.

Keywords: data, visualization, exhibitions, audience, learning

Improved access to data as well as changes in technology provide the opportunity to visualize historical data sets as physical spaces in museums. By examining existing models for spatialized data and considering interactions with visitors, we suggest that physical manifestations of data offer something notably different from data visualizations in print or on screen. These physical spaces that visualize data can evoke both historical and felt understanding, supporting the comprehension of historical data as well as an appreciation for the larger meaning of a historical moment. The application of this approach must also take into consideration the ethical and methodological questions faced by all humanities visualizations.

Two installations created from data 

In 2019, the United States Holocaust Memorial Museum (USHMM) in Washington, DC mounted two unusual installations. The first, the aptly named One Thousand Seventy-eight Blue Skies, includes 1,078 small, rectangular photographs of sky placed in seven large grids on a single wall outside of the museum’s main historical exhibition. Photographer Anton Kusters took these images between 2012 and 2017, traveling throughout Europe to capture one image at every known Nazi concentration camp and killing center across Europe.

The number of camps is meant to be surprising and was surprising to Kusters when he first started the project. In an interview, Kusters explains “It actually started for me as a way to understand. When I visited the first camp, I had no idea that there were so many camps, even though I learnt about Holocaust in school and at university, I never actually saw it in the way that I saw it when I went to Auschwitz first” (Vantage Editors, 2018). Researchers at the USHMM recently concluded that the Nazis and their collaborators created over 42,000 places of detention during the Holocaust – including these specific locations formally called “concentration camps.” 

The second installation, a briefly mounted prototype called Liquidation, appeared in an experimental gallery at the Holocaust Museum for four weeks in the summer of 2019. Liquidation grew from the work of two graduate students from Maryland Institute College of Art, Sarah Maravetz and Gillian McCallion. The pair designed a concept for the installation as part of a three-day residency at the Museum in 2017. Staff at the USHMM developed the prototype installation inspired by the original designs of Maravetz and McCallion.

Liquidation used sculptural elements, light, and projection to illustrate the growth and destruction of the Lodz ghetto during the Holocaust. The Germans created the Lodz ghetto in 1940, forcing over 160,000 Jews into a small section of the city under harsh conditions. Over the next four years, the ghetto population peaked at over 200,000 individuals. Most of the Jews from the ghetto were deported to killing centers including Chelmno and Auschwitz, and the ghetto was destroyed in 1944.

Drawing of glowing strands of light projected from the ceiling in a tight, uneven bundle.
Original concept for Liquidation by Sarah Maravetz and Gillian McCallion, 2017

While both projects included unusual elements for the institution: modern photography, rough prototyping materials, installation in new spaces, what truly distinguishes these installations is their use of historical data sets from the museum’s research and collections. One Thousand and Seventy-eight Blue Skies (Blue Skies) portrays data from the first volume of the USHMM’s Encyclopedia of Camps and Ghettos, 1933-1945 (Megargee, 2009). Kusters relied on the work to start his search for each camp location – though he often supplemented the volume with his own research into locations of camps that had yet to be identified. Liquidation adapted data that recorded the monthly population of the Lodz ghetto. Maravetz and McCallion have now graduated from MICA’s Information Visualization program and applied their understanding of data visualization to the original design.

Physical spaces as data visualizations

With both Blue Skies and Liquidation, historical data sets manifest as physical spaces inside the USHMM. Their designs use many traditional visualization methods but also give the data physical volume, going beyond the common projection of data into the flat spaces of pages or screens. The installations fit into a long history of data sets in physical form but also begin to raise questions about how museums – in this case, history museums – can harness the impact of spatialized data for their visitors.

Examples of spatialized data

Art as Physical Visualization

The Blue Skies installation builds on existing practices of the use of data visualization to create art. Kusters’ work represents a well-researched (and time consuming) artistic practice that builds from a premise – locating historic sites – and required considerable time and energy to complete the work. Kusters did not know about the USHMM’s encyclopedia project when he started. He did not start from a data set but the data became a major component of the work – ultimately outlining the number of places to be photographed, though not, unfortunately, all locations and other required data.

A 7 x 11 grid of small rectangles with images of the sky in varying shades of blue on a white background.
A section of a single panel from One Thousand Seventy-eight Blue Skies. United States Holocaust Memorial Museum. Photographer: Joel Mason-Gaines

For other artists, data sets can directly serve as the inspiration for works of art. The Renwick Gallery in Washington recently acquired Janet Echelman’s 1.8 – a work originally commissioned for the popular show Wonder. 1.8 fills the museum’s immense Grand Salon, creating an immersive space of color, fabric, and light. Echelman designed the artwork based on data from the earthquake and tsunami which hit Japan in 2011. Anne’s Magazine describes the project:

The forms in the sculpture and carpet were inspired by data sets of the Tsunami wave heights across the Pacific Ocean…It is a physical phenomena manifestation of interconnectedness – when any one element in the sculpture moves, every other element is affected (Anne’s Magazine, 2018).

It is not clear how precisely the installation matches the original data or how the mood of the piece, which is described as “playful” and “dreamlike” on the artist’s website, communicates the destructive power of the event represented in the data (Janet Echelman). Nonetheless, the data set behind 1.8 gives form to a space, shaping the cloth structures and appearing directly in the room’s carpets. 

More direct artistic placement of data in space can be found in works like Mount Fear East London by Abigail Reynolds. As described by artist Tom Corby, Reynolds’ work builds a physical sculpture mapping data from London police records on violent crime. The resulting mountainous cardboard structure allows audiences to physically encounter the data, walk around it and examine it in detail sufficient for analysis – at least by Corby’s estimate.

For Corby, artwork like Mount Fear East London and his own projected space, Cyclone.soc, break from the goals of scientific visualization to facilitate emotional encounters with data that create opportunities for embodied knowledge (Corby, 2008). Similarly, the spatial grid of Kusters’ Blue Skies intends to confront audiences with the physical scale of the concentration camp system. To use Corby’s language, when Blue Skies is viewed, their emotional response is related to an embodied understanding of the scale of the Holocaust.

Memorial Installations as Physical Visualizations

The Liquidation installation grows out of a tradition of memorialization. As originally conceived, the project created a somber space for visitors where they encountered the destruction of a community. Imagined as an enclosed space, Liquidation would include over 200,000 individual lights which would literally and figuratively dim as the inhabitants of the ghetto drained away. 

Many traditional memorial spaces have used data-like content, such as lists of names, for their construction. Based on Jewish tradition, Holocaust memorials often include symbolic or incomplete lists of names, as can be seen in memorial spaces like the “Book of Names” exhibit at the Auschwitz Memorial’s Block 27. Visitors to the exhibit can physically page through 4.2 million names gathered by Yad Vashem, the Israeli Holocaust memorial center, in their Central Database of Shoah Victims The names are inscribed in 58 volumes with 500 names per page. An additional volume of blank pages marks the absence of the millions of individuals killed in the Holocaust without record. Installed, the memorial fills 45 feet of exhibition space, giving a physical presence to the database of names.

The 9/11 Memorial in New York City also includes names, 2,982 names of victims of the attack, engraved around the two memorial fountains at the center of the site. Instead of organizing the data set into a regular grid by name or other simple sorting technique, the designer, Michael Arad, wanted the names ordered by the location and identity of each person. Family and friends of the deceased made over 1,000 requests for names to be placed in close proximity to others. Jake Barton, director of the design firm brought in for this aspect of the project, described the connections as “meaningful adjacency.” “They wanted to make a latticework of meaning underneath all those names. You have families clustered together, best friends, even incredible stories of strangers who died on that day…” (PBS News Hour, 2011).

To solve the problem of placing thousands of names according to thousands of possible connections, the design team turned to digital artist Jer Thorp. Thorp began by using a variety of techniques to cluster and comprehend the complexity of the relationships (Thorp, 2011). Ultimately, he built a series of algorithms that suggested the starting point for each name and the tools for designers to adjust the placement. As Thorp observes, neither humans nor computers could have completed the project on their own:

In this case, the computer was able to evaluate millions of possible solutions for the layout, manage a complex relational system, and track a large set of important variables and measurements. Humans, on the other hand, could focus on aesthetic and compositional choices. It would have been very hard (or impossible) for humans to do what the computer did (Thorp, 2011).

In both these examples, the data set directly manifests in the physical spaces in a way that is dependent on computational processing power. Yad Vashem’s Hall of Names, the basis for the Central Database, originally attempted to capture the names of victims on individual pieces of paper before the digitization process, a technique that had already become unwieldy with less than 2 million names. The names from the 9/11 Memorial relied on computational processes to make the design possible.

Memorial Spaces as Physical Visualizations

Finally, architectural approaches to memorialization have long given physical form to data sets but in a more expanded way than memorial installations. Memorial sites often use data to shape entire buildings or landscapes.

The National Memorial for Peace and Justice in Montgomery, Alabama creates an entire structure of 800 six-foot-tall steel blocks to represent individual U.S. counties – each bearing the names of the victims of racial violence killed there, often by lynching. In an opinion article for the online publication Hyperallergic, freelance writer William C. Anderson describes the monument: “The bold project of memorializing the uncountable number of Black lynching victims in the US is a hefty task. That awareness seems eerily present in the weight of the over 800 corten steel monuments (Anderson, 2018).”

The physical weight of the installation shapes the impact of the memorial as the viewer experiences what is essentially a data set. The memorial project identified a data set of lynching victims that has been given physical form by the designers. Bryan Stevenson, founder and executive director of the organization that created the memorial, describes the experience of seeing the space: “We wanted people to have a sense of just the scale of what this violence, what this terrorism was (Winfrey, 2018).”

Sculptures of chairs stand in a field to form a memorial at the Oklahoma City Bombing Memorial
Oklahoma City Bombing Memorial Photographed By Ken Lund, 2004. Creative Commons License.

Architects Torrey and Hans Butzer designed the Oklahoma City Bombing Memorial park to show data elements of the event including individuals, physical placement, and time. The memorial separates different data elements in the design – reserving the footprint of the destroyed building itself for the names of the victims (O’Connell). Within the footprint, symbolic empty chairs inscribed with one victim name each are organized by location within the building, allowing meaningful groupings similar to those used in the 9/11 Memorial. 

For these spaces – and many others – the entire environment has been shaped by historical information about individuals, events, and chronology. A greater amount of details in a data set allows for greater complexity in the built setting.

Installations as visualizations

Recontextualizing these experiences and others like them specifically as translations of data visualization into physical spaces provides several opportunities. First, existing knowledge about data visualization in the sciences and humanities can be applied directly to the physical spaces. Second, powerful physical spaces can support institutional goals outside of memorialization or artistic expression like, in the case of the USHMM, the understanding of history. Finally, close attention to visitor experience of these visual spaces can sharpen our understanding of how spatialized data differs from two-dimensional visualizations.

Visualization in other fields

It is not clear if the creators of most of the previous examples would consider their work to be “data visualizations.” Other fields, however, like scientific research and education, data journalism, and computer science have embraced visualization as an important tool for their practice. While these fields have a more mature approach to visualization than one finds in the humanities, their use of visualization continues to raise new questions and needs. In 2019, the Exploratorium hosted the conference VisualISE: Visualization for Informal Science Education. As the event’s proceedings make clear, the conference brought together a broad range of practices and experiences inside of and separate from informal science education to help clarify the goals and best practices of visualization (VisualISE, 2019). Common themes for practitioners included the need for more cross-disciplinary opportunities to convene expertise, synthesize shared knowledge, and create a shared vocabulary across fields (VisualISE, 2019, p.8).

Even within the existing literature on science visualization and greater practice at implementing visualizations for audiences, science museums still struggle to apply visualization techniques that can help their visitors understand the world around them (Ma, 2013). As the organizers of the VisualISE conference observe, most research into the use of visualization has taken place in controlled settings, far away from the active environment of museum galleries (VisualISE, 2019, p.9). 

If further research on the impact and methods of data visualization in informal settings continues to be needed in science education, how much more so will these techniques need to be explored with audiences in the humanities?

Human Computer Interaction and other related work in computer science also have established research about the impact of visualization.  Some work, like the research of Yvonne Jansen, look specifically at the possible benefits of creating physical versions of 3D visualizations to improve information retrieval (Jansen, 2013).   These and other studies can serve as a starting point for improving our understanding of how historical visualizations in physical spaces can impact audiences – though they seem primarily concerned with more concrete aspects of understanding.

Visualization in the humanities

Use of the data visualization techniques in the humanities – whether as digital interfaces or as physical spaces – should also be considered critically. A variety of researchers and practitioners have questioned the underlying assumptions in existing digital visualization methods and their limitations. 

Johanna Drucker, UCLA Professor of Bibliographic Studies, critiques the use of visualization techniques designed for quantitative analysis by humanities researchers (Drucker, 2011). Drucker argues that the very nature of these tools assumes the existence of subject-independent data, an impossibility for humanistic inquiry. Instead of relying on existing scientific tools for visualization, Drucker proposes the creation of tools and methods that “embody specific theoretical principles drawn from the humanities” (Drucker, 2012).

The creation of visualizations also has ethical implications. Michael Correll, a researcher with Tableau, argues against the perception of visualization and data as morally neutral – particularly within the practices of computer science and human computer interaction (Correll, 2019). Correll holds that all data collection and visualization is persuasive and outlines some of the ethical dangers emerging from current practice. He also suggests that practitioners’ responsibility to consumers of visualization should include obligations like “making the invisible visible” and “collecting data with empathy” that could serve as a starting place for more ethical practice (Correll, 2019, p. 7). 

Further application of physical visualization for use in museums will need also need to wrestle with these concerns and be part of the larger discussion in the field.

Experiencing physical visualizations 

While there are many examples of physical spaces that embody data sets, how do visitors understand the data within them? Because these spaces – particularly spaces based on humanities data – do not usually consider themselves to be data visualizations, there is limited information available for practitioners on the specific benefits this technique might have for visitors. The two recent projects at the USHMM provided the opportunity for informal conversations with visitors about their experiences that suggest areas for further exploration.

A variety of staff members engaged with visitors for these informal conversations as part of an exploratory process designed to support the application of new techniques and technologies to institutional practice. Staff interacted with and observed over 80 visitors (roughly 40 for each project). The themes described below emerged through open ended questioning. During the process, staff only spoke with visitors who specifically interacted with these installations.

Feeling the data

Emotional impact plays an important role in art and memorial installations and the response from visitors about both of the USHMM installations suggests these reactions can be quite complex. For the Liquidation installation, for example, visitors reacted most strongly to a sudden and significant drop in population shortly before the ghetto was closed in 1944. Unpacking visitor responses to this dramatic moment, several important themes emerged. Most obviously, visitors described an understanding of the historical moment that would not have been suggested by their reading of descriptive text. Comments described visitors connecting to the statistical data with an immediacy often missing from reading the numbers in a panel. Visitors themselves often recognized and contrasted the experience of witnessing the visualization directly with the act of reading and looking in exhibit spaces. They struggled to explain that they were learning the history but in a way that was different. As one visitor expressed their experience: “It is one thing to read a number in a book or on a display. It is another thing to see that number visually represented like this. I am just so moved and overwhelmed.”

Similarly, visitors described their experiences with the Blue Skies installation as a confrontation with the scale of the camp system – expressing their surprise at the number of camps and the ability of the installation to give them a sense of that scale that was different from the exhibition itself. Expression of the emotional response of visitors often included terms like “overwhelming” or “shocking.”

Intrigued by the visual

Visitors also reported that these installations drew them to learn more about the visualization. They used phrases like “intrigued by” or “drawn to” to describe how the physical presence of these installations invited them to learn more. Frequently, visitors would indicate that they could not understand the visualization at first glance but became curious enough to read and examine the installation. Often, a conversation would begin with a comment like “at first I didn’t know what it was but THEN…”

Anton Kusters specifically imagined this “second look” behavior for the Blue Skies installation. While not initially planned for Liquidation, a similar behavior pattern emerged. In the words of one visitor: “[I was] intrigued, not knowing what it was, since the lights were off. Wanted to come back to see what it was.” 

During the interview process for both projects, staff developed label text to support and simplify the process of quickly grasping the nature of the installation once a visitor became interested. Not every visitor wanted to take a second look at these visualizations and many passed by without a glance. While a full study of how many visitors would decide to engage with the installation was not possible, staff considered the wide variety of influences on viewing behavior. Many details likely influenced which visitors chose to engage with the visualization including issues like location of the installation in the gallery, the amount of time a visitor had already spent in the museum, the influence of other visitors, and personal interest.

Overview of the history

Both visualizations served as overviews of larger concepts for visitors. As already mentioned, the Blue Skies installation specifically evoked feelings of scale from visitors who often spoke of better understanding the reach of the concentration camp system. The immensity of the camp system can be seen as providing an overview specifically to the sections of the museum that discuss the camp system. Many visitors, however, also spoke of Blue Skies as an overview or summary of the entire exhibit. 

Several factors should be considered in this reaction from visitors. First, the placement of the installation at the end of the historical exhibition probably influenced the sense that it summarized the entire history. Second, the stories of the concentration camps play an oversized role in many visitors’ understanding of Holocaust history. Nonetheless, the response from the public suggests the potential for physical visualizations to frame larger ideas that can be explored in more detail by other exhibition elements.

Liquidation explored a much more narrow section of the history – the creation and destruction of a single ghetto during the Holocaust. Nonetheless, conversations with visitors suggested that the installation expressed larger ideas about ghettos in general. With the incorporation of projection and timeline information in Liquidation, some visitors considered (perhaps for the first time) that ghettos were dynamic environments where the population grew and shrank over time. One visitor summarized the changes in their understanding: “I didn’t know anything about it, didn’t understand the part that ghettos played in the movement of people. Just understanding [before viewing the installation] that people lost their lives there.”

Compression of data sets

Both visualizations can also be seen as compressing information. Blue Skies compresses all concentration camps into images of identical size and duration though, in truth, the camps ranged from holding hundreds of thousands of prisoners over the course of years to just a few prisoners in a span of weeks. Liquidation compresses four years of population data down to two and a half minutes.

These forms of compression are necessary for the legibility of the visualizations. Nonetheless, the institution must think responsibly about how this compression influences a visitor’s understanding. Though visitors did not recognize the compression itself, their reactions often demonstrated the importance of making decisions carefully.

While the Blue Skies images have been inscribed with estimated prisoner populations, this information is almost invisible to the viewer. Even with the installation’s success in expressing the scale of the camp system, visitor comments suggested that many still had a very limited historical understanding of the camps themselves. Similarly, showing monthly deportation numbers from the Lodz ghetto in a two and a half minute cycle emphasized the large number of deportations in August of 1944 when the ghetto was liquidated. During the development process, staff discussed a variety of ways to make sure that visualizations align with an accurate understanding of the historical record. Careful choices like selection of what is emphasized and how much and placement of a visualization with supporting text or within other exhibition contexts all play a part in minimizing the danger of creating a misleading visualization.

What did we learn?

Physical manifestations of data link the affective and intellectual experiences of our visitors. The creation of data visualizations as physical spaces is not new. As has been shown above there are many examples of how artists, architects, and designers have used data sets to shape the physical world. Instead, framing these physical installations as data visualizations creates the opportunity for museum practitioners to think of possible impacts for visitors beyond memorialization and artistic expression. The experiences of  visitors at the USHMM demonstrated that the strong affective response to data could help them to not only understand core concepts of Holocaust history but to recognize the impact of that history.

Further research in this area could help disentangle the unique traits of visualizations  as physical rather than screen- or print-based. One can expect that physical data visualizations share many of the same properties as their non-physical counterparts. The brief conversations with visitors at the USHMM were not enough to distinguish the distinct elements of these installations. A more formal study could help better understand the strengths and weaknesses of spatial visualization specifically. The visitor experience suggests that the power from these spaces comes from their presence. They create an immersive environment that envelops visitors in a meaningful space that they must interact with to understand. Future installations will help museum professionals to find further evidence of this idea and to better understand its implications.


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Cite as:
Haley Goldman, Michael and Pitcairn, Sara. "Physical Visualizations: Turning Data into Space." MW20: MW 2020. Published January 21, 2020. Consulted .