Madness part 1: visibility networks

March 31, 2014

ALL_SEEING_EYEI recently wrote I would keep you posted on my two months of madness in the run up to completing my PhD. Turns out I have very little time to write blog posts now … who would have guessed?!? But just to get things started, here is the first one. Let’s talk about the networks we can create using our eyes, let’s talk about visibility networks! I want to encourage everyone to comment and discuss these posts, I would really benefit from your input as I wrap up this four-year long struggle with the PhD beast.

One of my PhD’s case studies is on visibility networks. What are those, you ask? Well, they don’t really exist. That is to say, they are useful abstractions of possible past social phenomena. I use networks to represent whether past individuals standing on one point in a landscape, like a settlement, could see some other point in the landscape I am interested in, such as another settlement. This figure shows you how such a network could be created: an individual with a certain height standing on site A can see site B which is positioned somewhere else in a landscape, only if the view is not obstructed by hills or mountains. You can then represent this individual and the point he/she observes as points (or nodes in network terminology) and the line of sight from the observer to the observed point as a directed line (or arc in network terminology). Do this for tens or hundreds of observation locations and a complex network of lines of sight emerges.


Many people have asked me why this is useful. What do visibility networks add to existing approaches to studying past landscapes and settlement patterns, such as viewsheds in GIS for example? I like to believe I have a pretty good answer to this. Sometimes archaeologists are interested in understanding a past phenomenon that concerns the potential interactions between two entities, in which cases networks offer the best representation and analysis technique. To give an example, if we are interested in studying a past communication network that used fire or smoke signals to share information from one settlement to another (Like in Disney’s Mulan or in The Lord of the Rings), then evaluating the visibility of an entire landscape is overkill. All you need are the points and the lines. We do not have to analyse whether every square meter of a landscape was visible, but just that one point of interest. So selecting the best conceptualisation and abstraction of the past phenomenon you are interested in understanding can save you quite a lot of computing time. And it allows you to focus on representing and exploring your hypothesis, and not get distracted by other questions (if focus is what you want of course).

Mulan by Walt Disney

Mulan by Walt Disney

Moreover, we can do so much more once we have abstracted and represented our information about such a past communication system as a network. We can use network analysis techniques to determine the structure of this network, to compare it to other communication networks, to evaluate how efficient it was at sharing information, which settlements were key in sharing or blocking information, and so on. All of this offers a fresh new look on our data and provides results that can feed into our archaeological discussions and imaginations. Of course, the numbers a network analysis spits out are never the final word. They should always be re-contextualised in a wider archaeological research context rather than being taken at face value, or as an extra piece of  “primary information”.

I am definitely not the first archaeologist to have come up with the idea of visibility networks. Although it is not a very common topic, it has been done every once in a while in the past four decades, as you can see from the bibliogrpahy below this post. Many archaeologists focused their efforts on understanding signalling networks as described above (e.g. Shemming and Briggs, Swanson, Ruestes Bitrià). Another common phenomenon is the study of visual control, a popular topic in the study of Iron Age Spain (e.g. Grau Mira). There we see large fortified settlements on hilltops often called oppida, surrounded by smaller rural settlements. The oppida are often inter-visible with the rural settlements, whilst the rural settlements are less commonly inter-visible with one another. Archaeologists have suggested that this allowed for the oppida to visually control the smaller settlements, that it tells us something about social interactions between these communities, and possibly even about settlement hierarchies.

In following blog posts I will be giving you some more information about my efforts to explore such hypotheses of visual communication and control in Iron Age and Roman Southern Spain. Stay tuned!

Any thoughts or comments? Don’t hesitate to get in touch!

Archaeological studies of visibility networks:

Grau Mira, I. (2005). Romanization in Eastern Spain: a GIS approach to Late Iberian Iron Age landscape. In J.-F. Berger, F. Bertoncello, F. Braemer, D. Gourguen, & M. Gazenbeek (Eds.), Temps et espaces de l’homme en société, analyses et modèles spatiaux en archéologie. XXVième rencontres internatioales d’archéologie et d’histoire d’Antibes (pp. 325–334). Antibes: Éditions APDCA.

Grau Mira, I. (2004). La construcción del paisaje ibérico: aproximación SIG al territorio protohistórico de la Marina Alta. SAGVNTVN (P.L.A.V.), 36, 61–75.

Grau Mira, I. (2003). Settlement Dynamics and Social Organization in Eastern Iberia during the Iron Age (Eighth-Second Centuries BC). Oxford Journal of Archaeology, 22(3), 261–279. doi:10.1111/1468-0092.00187

Ruestes Bitrià, C. (2008). A Multi-technique GIS Visibility Analysis for Studying Visual Control of an Iron Age Landscape. Internet Archaeology, 23,

Shemming, J., & Briggs, K. (2013). Anglo-saxon communication networks. [accessed 4-10-2013]

Swanson, S. (2003). Documenting prehistoric communication networks: A case study in the Paquimé polity. American antiquity, 68(4), 753–767.

Prosopographies and social networks workshop

March 28, 2014

prosopProsopographies are great sources for building past social networks. Those interested in or working with large datasets of past individuals might be interested in the Prosop workshop. More information below. or on

Prosop: a social networking tool for the past

Call for participants

Second database development workshop

Florida State University (Tallahassee, FL) on May 9, 2014.

Historians and other scholars with large databases of historical person data are invited to a workshop to test and populate Prosop, a project funded by the Office of Digital Humanities of the National Endowment for the Humanities.

What is Prosop?

Prosop is a collaborative semantic web database of details about individuals in the past. Although it maps networks and discovers connections, it is not just facebook for dead people. In particular, it aims to:

  • manage diverse types of data from different historical settings,
  • aggregate of large quantities of person data,
  • accommodate uncertain and conflicting information, and
  • facilitate data-driven study of historical systems of description and classification.
  • For more detailed information, visit our website at

What kinds of data do we seek?

We’re looking for information about relatively large sets of relatively ordinary people from the past. Typically, this information is extracted from archival records used by microhistorians. For example, the database contains the name, age, address, and physical description of 700 criminal court defendants from 1880s Egypt. Prosop is meant to work for all kinds of historical person data, and we are especially interested in data in unusual formats (linguistic, topical, or otherwise) that will help us to develop the flexibility of the system. Also, we are looking for participants who are willing to share their data with the community of researchers using Prosop.

Applying with a counterpart

For this workshop, we are especially interested in applications from pairs of researchers who have similar datasets and would like to test them for possible overlap. Prosop may help them to discover common individuals and explore community characteristics.

What will happen at the workshops?

Before the workshop, each participant will submit a tranche of names, which will be imported into Prosop. Participants will describing the characteristics of their data and the ways it might interact with other person data. Those working in pairs will consider any overlap that Prosop found, as well as commonalities that it fails to discover. Participants will discuss issues of categorization and comparison that arise. We will work to find ways to link data and to make the system more usable. The workshop will provide a chance for historians and developers to communicate.

What’s in it for participants?

Workshop participants will contribute to the design of a tool that will enable new research into global social history, and will have early access to its results. They should gain new perspectives on their own data and its place in the global history of person information. Those working in pairs may discover fruitful overlap between their data sets. Participants’ experience and input will help to refine the system towards its aim, which is to encompass all categories of historical person data. Participant costs will be covered by the organizers, though some cost sharing may be asked of those applying from abroad.

How to apply?

Apply via the form available here. You will be asked to attach a CV and a letter of application, which should include a general description of the data which you wish to contribute to the project. Where possible, please specify:

  • the number of persons in the database
  • the categories of information recorded about each person (e.g. name, age, birthplace, occupation)
  • the geographical and chronological range of the persons represented
  • the type of sources from which the information is drawn (language, archives, genres).

What is the deadline for applications?

The deadline for applications for the second workshop is April 7, 2014.

Are there other ways to participate?

Prosop is an ongoing project. In addition to possible future workshops, we are looking for beta testers. If you are not able to join this workshop, but might want to be involved in the future, please get in touch via our website and join our mailing list.

CFP Student Conference Complexity Science

March 13, 2014

artworkThink your spaghetti monster networks are complex? Think again! The student conference on complexity science promises to reveal complexity in the most diverse things: fish, ant hills, traffic, and of course networks of every conceivable type. The University of Southampton’s Institute for Complex Systems Simulation is organising this year’s student conference in complexity science held in Brighton, bringing together a multi-disciplinary bunch of UK-based students crossing the physical and social sciences, as well as the Humanities (Archaeology will definitely be represented). Keynotes include Mark Newman (reason enough for networky people to attend), Nigel Gilbert (editor of JASSS), and Eörs Szathmáry (theoretical evolutionary biology). The Call for papers is out now and will be open until 14 April.

Check out the conference website for more info.

The Student Conference on Complexity Science (SCCS) is the largest UK conference for early-career researchers working under the interdisciplinary framework of Complex Systems, with a particular focus on computational modelling, simulation and network analysis. Since 2010, this conference series has brought together PhD students and early career researchers from both the UK and overseas, whose interests span areas as diverse as quantum physics, ecological food webs or the economics of happiness. This interdisciplinary nature of the conference is reflected by the diversity of keynote speakers as well as practical, hands-on workshops.

The SCCS is the perfect forum in which to present your work, discuss your ideas and gain useful skills. If your work comes under the umbrella of complexity science, then we want to hear from you! Thanks to the generosity of the Institute for Complex Systems Simulation we will be able to offer a number of student travel bursaries. The deadline for the call for abstracts is 14th April 2014.

CFP Simulating the past at ESSA, Barcelona

March 12, 2014

simulpastThe second call for papers is out for the ‘Simulating the past to understand human history’ conference, with further information on the pre-conference published proceedings and post-conference publication plans. More info here:

Dear Colleagues,

From September 1st to 5th, 2014, the European Social Simulation Association ( will celebrate its annual meeting in Barcelona (Spain), at the Universitat Autònoma de Barcelona (


On that occasion there will be the satellite conference, organized in collaboration with the Computer Applications and Quantitative Methods in Archaeology Society (


The conference is organized with the contribution of the SimulPast project (, a 5-year exploratory research project funded by the Spanish Government (MICINN, CSD2010-00034) that aims at developing an innovative and interdisciplinary methodological framework to model and simulate ancient societies and their relationship with environmental transformations. To achieve these aims, SimulPast integrates knowledge from diverse fields covering humanities, social, computational and ecological sciences within a national and international network.

The conference intention is to showcase the result of the SimulPast project together with current international research on the methodological and theoretical aspects of computer simulation in archaeological and historical contexts. The conference will bring together scholars from different disciplinary backgrounds (history, ecology, archaeology, anthropology, sociology, computer science and complex systems) in order to promote deeper understanding and collaboration in the study of past human behavior and history.

Invited Keynote speakers:

Dr. Timothy A. Kohler (Washington State University) (, and

Joshua M. Epstein (Center for Advanced Modeling in the Social, Behavioral and Health Sciences (CAM) at Johns Hopkins University) (

Applications are welcomed on all subjects (from Anthropology, Archaeology, Geography and Political or Economic History) using different approaches to social simulation and presenting case studies from any region of the world and any prehistoric or historic period. Theoretical aspects of social and cultural evolution are also encouraged.

The topics of interest include, but are not limited to:

Applications of computational modeling in archaeology and history
Social organization and change
Cultural transmission and evolution
Long term socio-ecology
Human adaptation and climate change
Cooperation and social interaction
Trade and exchange
Origins of State
Origins of Agriculture
Economic History
History of War and Conflict
Paleolithic, Neolithic
Ages of Metals
Greek and Roman History
Medieval History
Modern History

The Conference submission policy is:

Abstracts for oral presentations and posters (1000 words), Deadline: April, 11th., 2014
Once accepted, authors can submit full papers for the digital publication as a CEUR Workshop Proceedings Online for Scientific Workshops (with ISBN), and will be available before the Conference begins. Abstracts for oral presentations, posters and papers will also be freely available through Universitat Autonoma de Barcelona Digital Repository, and will be submitted for indexation by Thomson Reuters Conference Proceedings Citation Index (ISI) – Web of Science. Published contributions must have at least one author who has registered for the conference with payment by July 31th 2014 for the paper to appear in the proceedings. The proper link will be available in the next days. We apologize for the delay in updating the website!

There are three kinds of published contributions:

Full papers (10000 words)
Extended abstracts (4000 words
Posters (A3 format)
Deadline for Full papers, Extended Abstracts and Posters, June 15th.2014.

After the conference, a selection of the most relevant papers will be published as a book or special issue of a specialized journal. We are in the process of selecting the most suitable publisher: Cambridge UP, Oxford UP, Routledge, Francis & Taylor, Springer, etc.

For more information do not hesitate to contact the local organizers ( Detailed information, templates for submitting papers and EasyChair links for submissions and registration will be available at: Simulating the Past to Understand Human History is a special track of the SOCIAL SIMULATION-2014 Conference, so you should register at this conference to attend our special workshop. Deadlines, registration and submission procedures are the same for all satellite conferences at this event.

Given the coincidence with Union Internationale des Sciences Prehistoriques et Protohistoriques Meeting in Burgos (Spain) (, every effort will be made in order to allow interested researchers to assist to both Conferences. Burgos is well connected with Barcelona by plane (from Valladolid) or by train.

Juan A. BARCELO Associate Professor of Quantitative Archaeology Dept. Prehistory. Universitat Autonoma de Barcelona E-08193 Bellaterra Spain tel. +34935814335 personal web page:

Two months of insanity

March 10, 2014

Lindroth_The_Absent-minded_ProfessorIt’s finally there: the last two months of my PhD. Ever since I started almost four years ago everyone I talked to with a Dr. in front of their name told me the same thing, that the last few months are the hardest. It sounded as if when you finally decided to finish the damn thing off it starts putting up a fight. This usually finishes in the valiant PhD student winning the battle but loosing part of their sanity and most of their short-term memory in the process. My short-term memory is long gone (this is the main reasons why I claim to show promise for a career as an absentminded academic), but I have held on to my sanity. So far.

As I am working my way through my PhD in the coming two months I will document my struggle and loss of sanity on this blog, hoping it will end in victory. You can expect blog posts about all of the case studies I worked on in the last few years. In particular citation networks and visibility networks. But I will also share some of the conclusions I drew from working with network methods as an archaeologists, the challenges archaeologists are faced with, how we could confront these challenges, and my efforts to make a small contribution towards this. So stay tuned, and above all, please don’t hesitate to comment and provide me with your feedback on my work. I can use it now more than ever! 🙂

Data Ninjas VS Spaghetti Monster

March 3, 2014

puntoThere are some new kids on the network Science playground, and you better stay friends with them because they are here to kick ass. They call themselves the Data Ninjas. Introducing: “six degrees of spaghetti monsters“, the blog by the Leuven network researchers working with the Trismegistos database. The blog currently contains some interesting resources: books, links, blogs and the like. Soon the Data Ninjas will share results of their research so keep an eye on the blog. In the meantime, no better description of the ninjas than the one they provide on the blog:

All right folks! You found us! This means one of two things: either you’re friend/family/foe and you’re curious about what we’re up to (thanks for playing, better luck next time), or you’re seriously into SNA and you’re hoping to actually find some useful stuff here. We should pause here and warn you though: we are NOT SNA guru’s, despite us being worshipped by our department colleagues. We are, first and foremost, historians, lovers of all things antique (preferably Graeco-Roman in Egypt). And proud of it! About a year ago then, we started to explore the subtle science of social network analysis. We’ve come a long way since then, but we’re basically still rookies compared to the many die-hard sociologists, mathematicians, computer wizzes and all out there. RESPECT.
So basically what we’re aiming at with this blog is to let the world know what your tax money is spent on. Actually it’s just a very narcissistic self-promotional format. Science communication and valorization are the new buzz words when it comes to fellowship and grant applications, so we doing just that here. But buried deep down we still have an altruistic streak, so we’d also like to help out other self-taught, or wannabe self-teaching SNA’ers and to provide a forum where we can exchange thoughts and “experiments” (sounds pretty sciency huh? ¯\(°_⊙)/¯). We’re planning on posting some entries on the books and courses we’ve been using to get started, as well as on the software we’ve been playing with. And we’ll obviously keep you up-to-date on our research. We hope to present some AWESOME results here soon! Of course, this blog will be very history-oriented, so not all of our posts will be equally relevant for those of you who are working in other fields. But the beauty of SNA is that its basic principles are applicable to almost all types of networks, so we hope you’ll still enjoy our musings. And don’t hesitate to leave remarks, suggestions, questions, praise, cheers, jokes, your phone number, … We solemnly swear to reply as swiftly and as best as we can.
And we’re up to no good. Obviously.