Category Archives: method

When it comes to social media, YouTube is maybe the most understudied platform considering it’s enormous popularity in the context of popular culture, politics, and commerce. As part of a long term project on APIs from a software/platform studies perspective, but also in relation to the technical fieldwork required for data-driven empirical work, I have been testing the interfaces of quite a number of services now. To make this investigation productive beyond conceptual reflection, I’ve been building digital methods research tools for every system I look at. Nothing beats getting your hands dirty.

Since Google closed its search API some years ago, I haven’t really had a look at their services, but when a student of mine, Anouk Brouwer, started a thesis project on the booktube community on YouTube, I was not only fascinated by the booktube phenomenon and similar practices, but eager to revisit some older scripts and the new Data API v3 to see what kind of analyses would be possible. Google now has a centralized credential system for most of their APIs and a new quota framework where different calls cost different amounts of points. This sounds complicated, but since the quotas are extremely high (50M points/day, 3K calls/second), this is basically API dream land. After banging my head against Facebook’s technical and legal bureaucracy, it’s been extremely rewarding to work with a system that can take much, much more than I’m able to throw at it.

The outcome of this is a new set of scripts, called YouTube Data Tools (YTDT). You can try them out directly online or get the source code. For the moment, there are five modules that focus on different sections of the platform. The different features are explained in the tool interface, but I wanted to share a small experiment, made with the Channel Network module. This module starts from a set of channel ids and then crawls into the network constituted by YouTube’s featured channel feature (channels can “feature” other channels, basically just linking to them from their “channels” tab). The following image, made with gephi, shows a network of nearly 40k channels retrieved by starting with a single seed (the Vsauce channel) and crawling 7 steps into the network (click on the image for a much larger version, a PDF file is also available, as is the data):

youtube channel map

Since a number of channels do not make their view count available, node size and color encode the number of subscribers. I’ve deleted the labels for channels with fewer than 100k subscribers for better readability and used OpenOrd for spatialization. The network is strongly clustered, in particular around practices (gaming, fashion & makeup, etc.), languages, and corporate affiliations (e.g. the Vevo and Disney empires). I wasn’t entirely aware just how many people like to watch other people play games. YouTube is obviously much bigger than this, but the map should show a sizeable portion of the upper echelons of the YouTube hierarchy.

YTDT allows for many other kinds of analysis, and I am planning to introduce them in an overview video in the hopefully not too far future. This is still an early version, but maybe already useful to some people out there.

EDIT (13/05/2015): I made an introductory video:

EDIT (23/01/2015): Changed some text to make clear that you can still run Netvizz by grabbing the source code, registering a new app, and running it in developer mode.

EDIT (25/01/2015): I have written a small install guide for the source code on github. I’m unfortunately unable to help with individual problems, if you’re unfamiliar with server administration, your department’s tech support team should be able to help.

EDIT (28/01/2015): Since Facebook has changed the way apps are created, you can apparently no longer run just scripts requiring extended permissions in newly created apps, even in developer mode (making my source code useless for you). I have therefore whipped up a version of Netvizz that can only do pages and groups without requiring extended permissions. Since this does not have to go through review, you can use the app directly here.

EDIT (29/01/2015): Facebook’s policy review has accepted the new version of Netvizz (with personal network functions removed) and the app is again accessible here. API v1.0 is still going to be retired in April and this may pose problems, but this is something for another day.

EDIT (02/05/2015): API v1.0 has now been retired, but a new version of Netvizz (v1.2) has survived the changes and should continue functioning in the foreseeable future.

Original Post:

Today Netvizz, an app that allows researchers to download data from the Facebook platform, was suspended by the company and I received a mail explaining why:

Your app is violating the following Platform Policies:

Platform Policy Section 1: Build a quality product.
Platform Policy 1.1: Build an app that is stable and easily navigable.

Platform Policy 3.3: Only use friend data (including friends list) in the person’s experience in your app.

To clarify, your app should be stable and easy to use and shouldn’t stall escessively. Additionally, you should not allow friend data export, even if that data is anonymized. You can access the full list of our Platform Policies here:

Since Facebook has recently been very preoccupied with app privacy – for very good reasons actually – this does not come as a surprise. I have been anticipating API changes and the retirement of version 1.0 that comes with some very sensible changes in how data is delivered to platform apps for a while. Apps are clearly one of the biggest problems when it comes to Facebook’s privacy puzzle and most changes make a lot of sense. As Bernie Hogan wrote here, friendship connections are one of the casualties, as they will no longer be available to apps at all (v2.2 no longer makes them available). I was hoping to stall a little by moving to API v2.0, which still runs until April 2016, but this seems no longer viable after this morning’s news. As much as I agree with the general changes Facebook is making, I think it is a real shame that the analytical possibilities apps like Netvizz afford will no longer be available to researchers.

Over its roughly five year life span, what started as an inquiry into Facebook’s API, ultimately had over 60K unique users and analyzing their friendship network has been the start into graph analysis for many people. GetNet, a modified version of Netvizz, was used by Lada Adamic in her highly successful Coursera MOOC, allowing students to look at a network they are intimately familiar with, making network visualization much more tangible. GetNet actually still works, but will probably break in April 2015, if not shut down earlier.

For me personally, Netvizz has been a ambivalent project. On the one side, I enjoyed the tinkering with the API, but on the other, maintaining a complex tool in my spare time has often been a challenge. As anybody who offers software online for free will tell you, the mass of not always friendly emails can be daunting. I’m also not a computer scientist and I work in a humanities department, where technical work does not really count in performance reviews.

But the real problem with the current situation has little to do with me and much more with the many courses and research projects that have been relying on Netvizz. They are left out in the cold. So here are some elements that will hopefully help them deal with the situation:

  • Despite my hesitation to make software public that can be used very easily to download large amounts of non-anonymized data, there is so much code already in the wild that another set of scripts is not going to make much of a difference. I’m therefore making Netvizz’ source code publicly available. This should allow research projects relying on Netvizz to take the source code, register their own app at and run it in developer mode (just to make this clear, since I am the developer, I can actually still run the app, but it is no longer publicly available), which should work until April 30, 2015, the day v1.0 of the API retires. I apologize for the crappy code quality, this is one of those projects that grow and grow and never get a real redesign.
  • I will try to enter into further communication with Facebook to see what can be done, but I don’t expect much from that.
  • If that does not work, I will submit a version of Netvizz version for review that excludes personal network features and focuses on pages and groups. It’s still going to “stall excessively”, though, since it gets a lot of data.

I have no idea how long any of this make take. In the meantime, check out this list for alternatives, most of which hopefully still work. But make no mistake: this may well be the beginning of the end for external Facebook research with digital methods.

It’s a hot day in Amsterdam and writing is going slow. After reading this post on reddit, I ditched the writing for some playtime. In the post, /u/duckvimes_ charts the moderator overlaps between between /r/holocaust and a bunch of racist subreddits. The case is super interesting and the visualization very well done, but I thought that one could generalize the approach and create a map of reddit by looking at how subreddits’ moderators overlap. So I quickly wrote three scripts:

  • A script that gets the 10.000 most polular subreddits according to the GET_subreddits_popular API call.
  • A script that gets the moderator list for each of these subreddits
  • A script that generates a bipartite graph file containing all subreddits and moderators and connections between them

You can download a GDF file containing the 3000 most subscribed to subreddits file here.


To generate the visualization above (click for larger image, here’s a PDF), I used gephi‘s MultiMode plugin to transform the bipartite graph (which contains both subreddits and users) into a monopartite graph that connects two subreddits if they share a moderator; the more mods they share, the higher the link weight. In the visualization below, node size indicates number of subscribers and color the created date (blue => yellow => red indicates older to younger). Enjoy. (And now back to writing.)

After about two years of thinking and coding, my colleague Erik Borra and myself are happy to announce that the Digital Methods Initiative Twitter Capture and Analysis Toolkit (DMI-TCAT) is finally available for download. DMI-TCAT runs in a LAMP environment and allows for capturing data in a number of different ways via both the streaming and search APIs, and provides a whole battery of analytical approaches to investigating tweet collections. For a more detailed description check out the wiki on github. There is also a paper (paywall, preprint will follow) that details the tool and the thinking behind it.

Facebook is a nasty thing to study. It is much more complicated – in terms of interface, architecture, features, etc. – than Twitter for example. It has a lot of users and different types of interaction spaces. It is rather easy to extract a lot of data from it, particularly for companies creating apps and focusing on individual users and their network neighborhoods – but it is really difficult to get any kind of macro view. Pages and groups are the main “holes” through which researchers that don’t have an agreement with Facebook can get an idea about interaction patterns and the brand of publicness the service provides. Some time ago, I added page analysis features to netvizz and we’ve been doing some interesting things with that feature. A couple of months ago, I learned from Erik Hekman that the SQL code I used to extract friendship connections for ego networks and groups could actually be applied to any list of users. I am not yet fully sure how privacy settings affect this, but for a while now, the developer version of netvizz has been able to extract friendship connections between users active on a page. This feature will not make it into the public version (or maybe limited to a very low number of users), because the number of API calls necessary to get the connections grows with no of users^2 / 2, quickly leading to impossible waiting time. It’s still an interesting approach that merits a quick post.

The following network diagram (click for larger image) shows a bipartite graph containing the last 50 posts from the Facebook page of the European Green Party and the 3768 users liking or commenting posts. Posts are in black and users range from blue to red depending on the number of times they engaged with content on the page.


There are already quite a number of things one could say about the page using the standard netvizz data. But let’s have a look what friendship connections can add. The next diagram is exactly the same as the last one, but adds friendship connections between users in green (click for larger image).


There seems to be one pretty big group at the top that are a lot friends with each other and those are probably activists. The contents in that area seem to have to do with the official start of the campaign for the upcoming European Parliament elections. At the bottom slightly to the right is another dense cluster of users that one could qualify as issue audience – users that engage with topics such as GMOs or surveillance. The other two groups on the left are harder to qualify. I have to add an important point though. To facilitate comparability, I spatialized the nodes with friendship relations present. To generate the first diagram, I then simply removed those edges but left the layout intact. In the following image, though, I reapplied Mathieu Jacomy’s ForceAtlas 2 algorithm.


Now, only the edges encoding interaction or “engagement” between users and posts are taken account and the friendships no longer are. The way the posts are related to each other changes surprisingly little. Only the “asylum and migration” (a political initiative) post is placed a bit more to the top left, probably pulled by the top cluster of dense friendship connections. What that means, I guess, is that the engagement with content correlates with “social structure”, or whatever friendships on Facebook could meaningfully express. If the four tightly knit pockets were more heterogeneous in the way they engage with content, removing the friendship connections and rerunning the algorithm would have deformed the post distribution much more. If we consider that European parties have a quite fragmented party structure, this is not surprising. To probe a bit, I colored the interface language of the nodes in the next diagram (again back to spatialization with friendship connections taken into account, although they’re not shown in the image):


Certainly, there is some language clustering in the top group. And the one at the bottom, the one I called “issue audience” above, that’s the Germans. But still, this is a pretty diverse audience, very cool. There are clearly a lot of activists on that page, people traveling and exchanging, that’s why they are so connected. But the picture changes a little if we take the content out of the picture and look at friendship structure only:


First, we notice that most of the users are not connected to the big component in the middle; there’s a scattered audience next to the activists. Second, we see quite a large number of components with two or three nodes. These are very probably artifacts of Facebook’s architecture. If I like a post on a page, it has a certain chance of appearing in my friends’ newsfeed, where it can the be liked or commented on without every going to the page directly. I’ve seen these smaller components even more on other pages and this seems to be the most probable explanation. Third, despite stronger clustering without the content holding things together, there is still a very large connected component that comprises a bit over a third of the active users. Fourth, the most active users (the heat scale still shows number of engagements) are not necessarily the most connected ones.

To close off, two last diagrams, first with color encoding interface language:


This confirms the clustering by language/county, but also shows that there indeed is quite some mixing. Looking for the connectors between the countries clusters is relatively easy using betweenness centrality (color, again using a heat scale):


While netvizz provides node data in anonymized form, all of this stuff is available through the Facebook API with real names attached. I hope that users are aware at this point that pages are highly public spaces that can easily be profiled in quite some detail by anybody with a little programming skill. If I wanted to disrupt this organization, I’d start with the red dot in the last network diagram. Is it chilly in here?

This could be developed much further as well. But I am not sure yet how much weight one can put on the friendship data because of the question how much is missing because of privacy settings (which you may want to learn more about). The fact that obviously a lot of connections are publicly visible and relatively easy to harvest in small doses would merit much more discussion on its own. I am also pretty sure that big pages over large timespans are completely out of the question for reasons of the dreaded combinatorial explosion kicking in. Remember the rice corns on the chess board? And even if one would succeed in hammering the API, the data would be very difficult to analyze and to untangle. Lots of custom math needed; or a lot of patience; or both.

This could go nowhere but the results warrant a followup.

Of course, in the study of such complicated phenomena as occur in biology and sociology, the mathematical method cannot play the same role as, let us say, in physics. In all cases, but especially where the phenomena are most complicated, we must bear in mind, if we are not to lose our way in meaningless play with formulas, that the application of mathematics is significant only if the concrete phenomena have already been made the subject of a profound theory.

A. D. Aleksandrov, A General View of Mathematics. In: A. D. Aleksandrov, A. N. Kolmogorov, M. A. Lavrent’ev, Mathematics: Its Content, Methods and Meaning. Moscow 1956 (trans. 1964)

Over the last couple of weeks, things have heated up considerably for Google – on the mobile side with the start of a patent war, but also in the search area, the core of the company’s business. Led by Senator Mike Lee (a Utah Republican), the US Senate’s Antitrust Subcommittee has started to probe into certain aspects of Google’s ranking mechanisms and potential cases of abuse and manipulation.

In a hearing on Wednesday, Lee confronted Eric Schmidt with accusations of tampering with results and the evidence the Senator presented was in fact very interesting because it raises the question of how to show or even prove that a highly complex algorithmic procedure “has been tampered with”. As you can see in this video, a scatter-plot from an “independent study” that compares the search ranking for three price comparison sites (Nextag, Pricegrabber, and Shopper) with Google Price Search using 650 shopping related queries. What we can see on the graph is that while there is considerable variation in ranking for the competitors (a site shows up first for one query and way down for another), Google’s site seems to consistently stick to place three. Lee makes this astounding difference the core of his argument and directly asks Schmidt: “These results are in fact the result of the same algorithm as the rankings for the other comparison sites?” The answer is interesting in itself as Schmidt argues that Google’s service is not a product comparison site but a “product site” and that the study basically compares apples to oranges (“they are different animals”). Lee then homes in on the “uncanny” statistical regularity and says “I don’t know whether you call this a separate algorithm or whether you’re reverse engineered a single algorithm, but either way, you’ve cooked it!” to which Schmidt replies “I can assure you that we haven’t cooked anything.”

According to this LA Times article, Schmidt’s testimony did not satisfy the senators and there’s open talk about bias and conflict of interest. I would like to add to add three things here:

1) The debate shows a real mismatch between 20th century concepts of both bias and technology and the 21st century challenge to both of these question that comes in the form of Google. For the senator, bias is something very blatant and obvious, a malicious individual going to the server room at night, tempering with the machinery, transforming the pure technological objectivity into travesty by inserting a line of code that puts Google to third place most of the time. The problem with this view is of course that it makes a clear and strong distinction between a “biased” and an “unbiased” algorithm and clearly misses the point that every ranking procedure implies a bias. If Schmidt says “We haven’t cooked anything!”, who has written the algorithm? If it comes to an audit of Google’s code, I am certain that no “smoking gun” in the form of a primitive and obvious “manipulation” will be found. If Google wants to favor its own services, there are much more subtle and efficient ways to do so – the company does have the best SEO team one could possibly imagine after all. There is simply no need to “cook” anything if you are the one who specifies the features of the algorithm.

2) The research method applied in the mentioned study however is really quite interesting and I am curious to see how far the Senate committee will be able to take the argument. The statistical regularity shown is certainly astounding and if the hearings attain a deeper level of technological expertise, Google may be forced to detail a significant portion of its ranking procedures to show how something like this can happen. It would, of course, be extremely simple to break the pattern by introducing some random element that does not affect the average rank but adds variation. That’s also the reason why I think that Lee’s argument will ultimately fizzle.

3) The core of the problem, I would argue, is not so much the question of manipulation but the fact that by branching into more and more commercial areas, Google finds itself in a market configuration where conflicts of interest are popping up everywhere they turn. As both a search business and an actor on many of the markets that are, at least in part, ordered by the visibility layering in search results, there is a fundamental and structural problem that cannot be solved by any kind of imagined technical neutrality. Even if there is no “in house SEO” going on, the mere fact that Google search prominently links to other company services could already be seen as problematic. In a sense, Senator Lee’s argument actually creates a potentially useful “way out”: if there is no evil line of code written in the dark of night, no “smoking gun”, then everything is fine. The systematic conflict of interest persists however, and I do not believe that more subtle forms of bias towards Google services could be proven or even be seriously debated in a court of law. This level of technicality, I would argue, is no longer (fully) in reach for this kind of causal demonstration. Not so much because of the complexity of the algorithms, but rather because the “state” of the machine includes the full structure of the dataset it is working on, which means the full index in this case. To understand what Google’s algorithms actually do, looking at these algorithms without the data is no longer enough. And the data is big. Very big.

As you can see, I am quite pessimistic about the possibility to bring the kind of argumentation presented by Senator Lee to a real conclusion. If the case against Microsoft is an indicator, I would argue that this pessimism is warranted.

I do believe that we need to concentrate much more on the principal conflicts of interest rather than actual cases of abuse that may be simply too difficult to prove. The fundamental question is really how far a search company that controls such a large portion of the global market should be allowed to be active in other markets. And, really, should a single company control the search market in the first place? Limiting the very potential for abuse is, in my view, the road that legislators and regulators should take, rather than picking a fight over technological issues that they simply cannot win in the long run.

EDIT: Google has compiled its own Guide to the Hearing. Interesting.

Simondon’s Du mode d’existence des objets techniques from 1958 is a most wondrous book. It is not only Simondon’s theory of technology in itself that fascinates me, but rather the intimate closeness with particular technical objects that resonates  through the whole text and marks a fundamental break with the greek heritage of thinking about technology as a unified and coherent force. When Simondon reasons over numerous pages on the difference between a diode and a triode, he accords significance to something that was considered insignificant by virtually every philosopher in history. By conferring a sense of dignity to technology, a certain profoundness, he is able to see heterogeneity and particularity where others before him just saw the declinations of the singular principle of techné. In a distinctly beautiful passage, Simondon argues that “technological thinking” itself is not totalizing but fragmenting:

“L’élément, dans la pensée technique, est plus stable, mieux connu, et en quelque manière plus parfait que l’ensemble ; il est réellement un objet, alors que l’ensemble reste toujours dans une certaine mesure inhérent au monde. La pensée religieuse trouve l’équilibre inverse : pour elle, c’est la totalité qui est plus stable, plus forte, plus valable que l’élément.” (Simondon 1958, p. 175)

And my translation:

“In technological thinking, it is the element that is more stable, better known and – in a certain sense – more perfect than the whole; it is truly an object, whereas the whole always stays inherent to the world to a certain extend. Religious thinking finds the opposite balance: here, it is the whole that is more stable, stronger, and more valid than the element.”

Philosophical thinking, according to Simondon, should strive to situate itself in the interval that separates the two approaches, technological thinking and religious thinking, concept and idea, plurality and totality, a posteriori and a priori. Here, the question of How? is not subordinate to the question of Why? because it is the former that connects us to the world that we inhabit as physical beings. Understanding technology means understanding how the two levels relate and constitute a world. There are two forms of ethics and two forms of knowledge that must be combined both intellectually and practically. Simondon obviously strives to do just that. I would argue that Philip Agre’s concept of critical technical practice is another attempt at pretty much the same challenge.

There are many different ways of making sense of large datasets. Using network visualization is one of them. But what is a network? Or rather, which aspects of a dataset do we want to explore as a network? Even social services like Twitter can be graphed in many different ways. Friend/follower connections are an obvious choice, but retweets and mentions can be used as well to establish links between accounts. Hashtag similarity (two users who share a tag are connected, the more they share, the closer) is yet another method. In fact, when we shift from interactions to co-occurrences, many different things become possible. Instead of mapping user accounts, we can, for example, map hashtags: two tags are connected if they appear in the same tweet and the number of co-occurrences defines link strength (or “edge weight”). The Mapping Online Publics project has more ideas on this question, including mapping over time.

In the context of the IPRI research project we have been following 25K Twitter accounts from the French twittersphere. Here is a map (size: occurrence count / color: degree / layout: gephi with OpenOrd) of the hashtag co-occurrences for the 10.000 hashtags used most often between February 15 2011 and April 15 2011 (clicking on the image gets you the full map, 5MB):

The main topics over this period were the regional elections (“cantonales”) and the Arab spring, particularly the events in Libya. The japan earthquake is also very prominent. But you’ll also find smaller events leaving their traces, e.g. star designer Galliano’s antisemitic remarks in a Paris restaurant. Large parts of the map show ongoing topics, cinema, sports, general geekery, and so forth. While not exhaustive, this map is currently helping us to understand which topics are actually “inside” our dataset. This is exploratory data analysis at work: rather than confirming a hypothesis, maps like this can help us get a general understanding of what we’re dealing with and then formulate more precise questions from there.

When Lawrence Lessig famously stated that “code is law”, the most simple and striking example was AOL’s decision to – arbitrarily – limit the number of people that could log into a chat room at the same time to 23. While the social consequences of this rule were quite far-reaching, they could be traced to a simple line of text somewhere in a script stating that “limit = 23;” (apparently someone changed that to “limit = 36;” a bit later).

When starting to work on a data exploration project linking Web sites to Twitter, I wasn’t aware that the microblogging site had similar limitations built in. Somewhere in 2008, Twitter apparently capped the number of people one can follow to 2000. I stumbled over this limit by accident when graphing friends and followers for the 24K+ accounts we are following for our project:

This scatterplot (made with Mondrian, x: followers / y: friends) shows the cutoff quite well but it also indicates that things are a bit more complicated than “limit = 2000;”. From looking at the data, it seems that a) beyond 2000, the friend limit is directly related to the number of followers an account has and b) some accounts are exempt from the limit. Just like everywhere else, there are exceptions to the rule and “all are equal before the law” (UN Declaration of Human Rights) is a standard that does not apply in the context of a private service.

While programmed rules and limits play an important role in structuring possibilities for communication and exchange, a second graph indicates that social dynamics leave their traces as well:

This is the same data but zoomed out to include the accounts with the highest friend and follower count. There is a distinct bifurcation in the data, two trends emerging at the same time: a) accounts that follow the friend/follower limit coupling and b) accounts that are followed by a lot of others while not following many people themselves. The latter category is obviously celebrity accounts such as David Lynch, Paul Krugman, or Karl Lagerfeld. These brands are simply using Twitter as a one-to-many medium. But what about the first category? A quick examination confirms that these are Internet professionals, mostly from marketing and journalism. These accounts are not built on a transfer of social capital (celebrity status) from the outside, but on continuous cross-platform networking and diligent posting. They have to play by different rules than celebrities, reciprocating follower connections and interacting with other accounts to abide by the tacit rules of the twitterverse. They have built their accounts into mass media as well but had to work hard to get there.

These two examples show how useful data visualization can be in drawing our attention to trends in the data that may be completely invisible when looking at the tables only.