Later this month, we’re lucky to have Jari Saramäki visiting and speaking at the lab. Jari is an expert on temporal networks (I highly recommend the excellent review paper on temporal networks that Jari co-authored with past and future guest of the lab, Petter Holme).

Jari is an associate professor at Aalto University and a highly cited author of many high impact papers on complex networks, for example:

  • Jari Saramäki, E. A. Leicht, Eduardo López, Sam G. B. Roberts, Felix Reed-Tsochas, and Robin I. M. Dunbar. Persistence of social signatures in human communication. PNAS 111 (3) 942-947 (2014).
  • Lauri Kovanen, Kimmo Kaski, János Kertész, and Jari Saramäki. Temporal motifs reveal homophily, gender-specific patterns, and group talk in call sequences. PNAS 110 (45) 18070-18075 (2013).
  • J.-P. Onnela, J. Saramäki, J. Hyvönen, G. Szabó, D. Lazer, K. Kaski, J. Kertész, and A.-L. Barabási. Structure and tie strengths in mobile communication networks. PNAS 104 (18) 7332-7336 (2007).

Below are the details of his talk.

From minutes to months: call network dynamics at multiple timescales

  • Date: 27th of January
  • Time: 14:00
  • Location: Auditorium 040 in DTU Building 324.

Abstract: Big Data on human interactions and communication have revolutionized the ways how human behaviour can be approached from a quantitative point of view. Mobile telephone Call Detail Records (CDR’s) have proven especially fruitful for understanding one-to-one communication patterns and the dynamics of inferred social networks. I will discuss what happens and when in call networks constructed from CDR’s with time stamps; this talk can be considered a mini-review of what we know about temporal networks of mobile telephone calls. I will begin with short timescales and fast dynamics (such as burstiness of sequences of calls between individuals) and “zoom out”, from temporal motifs formed of correlated calls between multiple individuals to long-term dynamics of personal networks of individuals.

Privacy Part I: Why everyone is complaining, but no one is taking action.

[This is part II of a series, you can find the overview here]

We all have a sense that privacy is important. A sense that our ability to freely express “who we are” is slowly eroded by large corporations and governments collecting data on our actions for purposes not clear to us (and maybe not to them either). But on the other hand, no one is doing anything about this. Why is that?

I think that there are two central reasons for this.

The first reason is that humans are not very good at handling situations where cause and effect is separated by a lots of time and space. (I was made aware of this point by an excellent column in the Guardian by the author Cory Doctorow, who I will be stealing from in the following). There are lots of examples of this: No one would smoke if you developed cancer immediately upon the first drag of a cigarette. The possibility of cancer is so far away in time that it feels like the consequences happen to another person. You would be less likely to  binge-eat if the food immediately was converted into belly flab.

Something similar is going on with privacy. You don’t immediately notice any problems when you hand over all of your email correspondence to Google or outsource your social network to Facebook, or signing up for free Airport Wifi. And it’s even worse because we don’t even know what the consequences of sharing those data might be. Figuring out what we can learn about individuals is an emerging field. And while we know that you can estimate e.g. your political views based on your Facebook feed, we’re still working out what it really is that you’re revealing about yourself, when you’re sharing data … and how those pieces of information can be used to manipulate you.

In fact, the entities that know most about what your personal data can be used for (e.g. Google, Facebook, Apple, Amazon), have very little incentive to share this information with the general public. In part because opening up can damage their public image (e.g. the Facebook mood experiment), and in part because sharing insights might run counter to shareholder interests (e.g. making tons of $$$ manipulating people) [1]. This is why the kind of research that we do here at DTU is so important – providing a public and open counterpoint to large corporation with private research divisions.

The second (and even more important) reason is that it is not at all clear what kind of action we should take. Privacy is such a complex issue that even if you want to take action, there is no obvious path to follow. To make such a path a little bit clearer is, my goal with the posts in this series. I’ll try to find a little bit of solid ground so that maybe we’ll have something to mobilize around once we feel like it’s time to take action.


[1] Thanks to Piotr Sapiezynski for making this point.