This year was packed with things we’re excited about and want to celebrate and share. Great things happened to Community Data Science Collective members within our schools and the wider research community.
Charlie Kiene and Regina Cheng completed their comprehensive exams and are now PhD candidates!
Nate TeBlunthuis defended his dissertation and started a post-doctoral fellowship at Northwestern. Jim Maddock defended his dissertation on December 16th.
Regina was a teaching assistant for senior undergraduate students on their capstone projects. Regina’s mentees won Best Design and Best Engineering awards.
Salt was interviewed on the FOSS and Crafts podcast. His conference presentations included Linux App Summit, SeaGL and DebConf. Kaylea Champion spoke at SeaGL and DebConf. Kaylea’s DebConf present was on her research on detecting at-risk projects in Debian.
Champion, Kaylea. 2021. “Underproduction: An approach for measuring risk in open source software.” 28th IEEE International Conference on Software Analysis, Evolution and Reengineering (SANER). pp. 388-399, doi: 10.1109/SANER50967.2021.00043.
Fiers, Floor , Aaron Shaw , and Eszter Hargittai. 2021. “Generous Attitudes and Online Participation.” Journal of Quantitative Description: Digital Media, 1. https://doi.org/10.51685/jqd.2021.008
Hill, Benjamin Mako , and Aaron Shaw , 2021. “The hidden costs of requiring accounts: Quasi-experimental evidence from peer production.” Communication Research 48(6): 771-795. https://doi.org/10.1177%2F0093650220910345.
Hwang, Sohyeon and Jeremy Foote . 2021. “Why do people participate in small online communities?”. Proceedings of the ACM on Human-Computer Interaction, 5(CSCW2), 462:1-462:25. https://doi.org/10.1145/3479606
Shaw, Aaron and Eszter Hargittai. 2021. “Do the Online Activities of Amazon Mechanical Turk Workers Mirror Those of the General Population? A Comparison of Two Survey Samples.” International Journal of Communication 15: 4383–4398. https://ijoc.org/index.php/ijoc/article/view/16942
TeBlunthuis, Nathan , Benjamin Mako Hill , and Aaron Halfaker. 2021. “Effects of Algorithmic Flagging on Fairness: Quasi-experimental Evidence from Wikipedia.” Proc. ACM Hum.-Comput. Interact. 5, CSCW1, Article 56 (April 2021), 27 pages. https://doi.org/10.1145/3449130
TeBlunthuis, Nathan. 2021 “Measuring Wikipedia Article Quality in One Dimension.” In Proceedings of the 17th International Symposium on Open Collaboration (OpenSym ’21). Online: ACM Press. https://doi.org/10.1145/3479986.3479991.
The OG Mechanical Turk (public domain via Wikimedia Commons). It probably was not useful for unbiased survey research sampling either.
When it comes to research about participation in social media, sampling and bias are topics that often get ignored or politely buried in the "limitations" sections of papers. This is even true in survey research using samples recruited through idiosyncratic sites like Amazon’s Mechanical Turk. Together with Eszter Hargittai, I (Aaron) have a new paper (pdf) out in the International Journal of Communication (IJOC) that illustrates why ignoring sampling and bias in online survey research about online participation can be a particularly bad idea.
Surveys remain a workhorse method of social science, policy, and market research. But high-quality survey research that produces generalizable insights into big (e.g., national) populations is expensive, time-consuming, and difficult. Online surveys conducted through sites like Amazon Mechanical Turk (AMT), Qualtrics, and others offer a popular alternative for researchers looking to reduce the costs and increase the speed of their work. Some people even go so far as to claim that AMT has "ushered in a golden age in survey research" (and focus their critical energies on other important issues with AMT, like research ethics!).
Despite the hype, the quality of the online samples recruited through AMT and other sites often remains poorly or incompletely documented. Sampling bias online is especially important for research that studies online behaviors, such as social media use. Even with complex survey weighting schemes and sophisticated techniques like multilevel regression with post-stratification (MRP), surveys gathered online may incorporate subtle sources of bias because the people who complete the surveys online are also more likely to engage in other kinds of activities online.
Surprisingly little research has investigated these concerns directly. Eszter and I do so by using a survey instrument administered concurrently on AMT and a national sample of U.S. adults recruited through NORC at the University of Chicago (note that we published another paper in Socius using parts of the same dataset last year). The results suggest that AMT survey respondents are significantly more likely to use numerous social media, from Twitter to Pinterest and Reddit, as well as have significantly more experiences contributing their own online content, from posting videos to participating in various online forums and signing online petitions.
Such findings may not be shocking, but prevalent research practices often overlook the implications: you cannot rely on a sample recruited from an online platform like AMT to map directly to a general population when it comes to online behaviors. Whether AMT has created a survey research "golden age" or not, analysis conducted on a biased sample produces results that are less valuable than they seem.
Should online communities require people to create accounts before participating?
This question has been a source of disagreement among people who start or manage online communities for decades. Requiring accounts makes some sense since users contributing without accounts are a common source of vandalism, harassment, and low quality content. In theory, creating an account can deter these kinds of attacks while still making it pretty quick and easy for newcomers to join. Also, an account requirement seems unlikely to affect contributors who already have accounts and are typically the source of most valuable contributions. Creating accounts might even help community members build deeper relationships and commitments to the group in ways that lead them to stick around longer and contribute more.
In a new paper published in Communication Research, Benjamin Mako Hill and Aaron Shaw provide an answer. We analyze data from “natural experiments” that occurred when 136 wikis on Fandom.com started requiring user accounts. Although we find strong evidence that the account requirements deterred low quality contributions, this came at a substantial (and usually hidden) cost: a much larger decrease in high quality contributions. Surprisingly, the cost includes “lost” contributions from community members who had accounts already, but whose activity appears to have been catalyzed by the (often low quality) contributions from those without accounts.
The full citation for the paper is: Hill, Benjamin Mako, and Aaron Shaw. 2020. “The Hidden Costs of Requiring Accounts: Quasi-Experimental Evidence from Peer Production.” Communication Research, 48 (6): 771–95. https://doi.org/10.1177/0093650220910345.
Thinking about applying to graduate school? Wonder what it’s like to pursue a PhD? Interested in understanding relationships between technology and society? Curious about how to do research on online communities like Reddit, Wikipedia, or GNU/Linux? The Community Data Science Collective is hosting a Q&A on November 5th at 13:00 ET / 12:00 CT / 10:00 PT for prospective students. This session is scheduled for an hour, to be divided between a larger group session with faculty and then smaller groups with current graduate students.
This is an opportunity for prospective grad students to meet with CDSC faculty, students, and staff. We’ll be there to answer any questions you have about the group, the work we do, your applications to our various programs, and other topics. You can either submit a question ahead of time or ask one during the session.
About the CDSC
We are an interdisciplinary research group spread across Carleton, Northwestern University, Purdue University, and the University of Washington. (Carleton is not accepting graduate students, though the other universities are.) You can read more about PhD opportunities on our blog.
We are mostly quantitative social scientists pursuing research about the organization of online communities, peer production, online communities, and learning and collaboration in social computing systems. Our group research blog and publications page can tell you more about our work.
Notes About Attending
We are so excited to meet you! Please RSVP online to let us know if you’re coming. This form also gives you the opportunity to ask a question ahead of time. By doing this, we’ll be able to make sure we get to your questions.
We will post another announcement with attendance information. We will also email attendance details to all registered attendees.
The conference will feature two new papers by collective students and faculty that were published in the journal Proceedings of the ACM on Human-Computer Interaction: CSCW.
Information on the talks as well as links to the papers are available here (CSCW members are listed in italics):
In addition, Benjamin Mako Hill is a panel co-chair.
Mako, Sohyeon, Jeremy, and Nathan will all be at the conference and so will tons of our social computing friends. Please come and say “Hello” to any of us and introduce yourself if you don’t already know us :)
Accurately estimating the quality of Wikipedia articles is important task for both researchers and Wikipedia community members. In a forthcoming paper in the Proceedings of the OpenSym 2021, I describe a new method for estimating article quality in Wikipedia in one dimension that builds on the widely used ORES quality model and that improves on the techniques researches have used to incorporate measures of quality into their studies of Wikipedia in the past. I will presenting virtually this week at the OpenSym 2021 conference. OpenSym is free and open to the public this year but requires registration.
Numerous efforts have gone into measuring the quality of Wikipedia articles and the Wikimedia Foundation maintains a machine learning model for measuring article quality on English Wikipedia called the ORES quality model. This model is trained on quality assessments conducted by members of WikiProjects that label articles into hierarchy of quality levels (i.e., stub, start-class, C-class, B-class, Good, Featured) and use boosted decision trees to predict the quality of versions of articles. This model is useful because it can predict the quality of versions of articles that haven’t been assessed. My OpenSym paper (teaser video, full presentation) builds on the ORES quality models to improve measuring Wikipedia article quality in one continuous dimension using ordinal regression models. A 1-D real-valued measure of quality is more granular and easier to use in downstream research. My method also increases the accuracy of quality prediction for units of analysis that are most important for research like articles or revisions and also estimates spacing between different levels of article quality.
Quality scores and predictions of the ordinal regression models. Columns in the grid of charts correspond to the ordinal quality model calibrated to the indicated unit of analysis and rows correspond to sampled articles having the indicated level of quality as assessed by Wikipedians. Each chart shows the histogram of scores, thresholds inferred by the ordinal model with 95% credible intervals colored in gray, and colors indicating when the model makes correct or incorrect predictions. The thresholds are not evenly spaced, especially in revision model and article model that have more weight on lower quality classes. These two models infer that the gaps between Stub and Start and between Start and C-class articles are considerably wider than the gap between C-class and B-class articles.
An important limitation of the ORES quality models is that they do not output a single real-valued quality score. Instead, they output a multinomial distribution of the probability of an article’s quality class. This means that instead of saying “article X has quality 0.3” the model tells you “the probability of article X’s quality class is 0.1 for stub, 0.2 for start-class, 0.5 for C-class, 0.15 for B-class, 0.05 for Good and 0 for featured and the most probable quality class (MPQC) is C.” Using this kind of output in a downstream statistical analysis is kind of messy. For example, it might seem reasonable to use the MPQC as an integer-valued measure of quality, but this throws away information. Suppose ORES says that “the probability of article Y’s quality class is 0.00 for stub, 0.15 for start-class, 0.5 for C-class, 0.2 for B-class, 0.1 for Good, and 0.05 for Featured” According to the ORES quality model, Y probably has greater quality than X. Even though both have a MPQC of C-class, there’s a much greater change for article Y to be B-class or better than for article X. Is there a way to use the ORES probabilities to build a more granular measure of quality that accounts for this difference?
Aaron Halfaker, one of the creators of the ORES system, combined the probabilities into a 1-D score for one of his research projects by taking a weighed sum of the probabilities and assuming that Wikipedia article quality levels are “evenly spaced.” This creates a score out of the quality class probabilities by multiplying each probability by a weight so that probabilities for higher quality levels get more weight. He chose the weights [0,1,2,3,4,5] so an article gets 0 quality points for being a probable stub, 1 for the probability of being start-class, 2 for C-class, and so on with 5 points for Featured. This results in a nice continuous measure of quality that simplifies downstream statistical analysis. A number of others have followed his lead.
But how reasonable is the “evenly spaced” assumption that supports using the weights [0,1,2,3,4,5]? Could there be a way to pick weights to combine the ORES probabilities without using this assumption? My paper explains why ordinal regression is the right tool for the job and proposes a procedure for fitting an ordinal regression model to a sample representative of a unit of analysis like articles or revisions or quality classes that have been labeled by a WikiProject and scored by the ORES quality model. The ordinal regression predicts the quality labels as a function of the ORES scores and in this way finds a good way to combine the ORES scores into a single value. It also infers threshold parameters that define different regions of the quality score corresponding to quality classes and this allows the “evenly spaced” assumption to be tested. The figure above shows that the article quality levels are not evenly spaced! Interestingly, the way that they are unevenly spaced depends on how quality is measured. If the quality scale is designed to be accurate across all quality classes, then the quality levels are relatively even. However, if it is designed to be accurate for revisions or articles then more of the scale goes to lower levels of quality. Overall, the models agree that the difference between C-class and Start articles is smaller than that between the other levels.
Using the quality scores based on ordinal regression also improves accuracy. This mostly comes from calibrating the ordinal model to the appropriate unit of analysis. The ORES quality model is fit on a “balanced” dataset where each quality class is equally represented. This means that the ORES quality model has learned that each quality class is equally likely to occur in the data. Of course, in reality lower quality articles are far more common than high quality articles. There are over 3,000,000 Stubs on English Wikipedia but less than 8,000 Featured articles. As the table below shows, fitting ordinal models that know the true proportion of each quality class in a sample can improve accuracy compared to the ORES quality model.
Accuracy of quality prediction models depends on the unit of analysis. The greatest accuracy scores are highlighted. Models are more accurate when calibrated on the same unit of analysis on which they are evaluated. Compared to the MPQC, the ordinal quality models have better accuracy when revisions or articles are the unit of analysis. When the quality class is the unit of analysis, the ordinal quality model has slightly worse accuracy.
Even though my study has found evidence against the “evenly spaced” assumption, I also found that the quality scores based on it are strongly correlated with the scores from the ordinal model as shown in the figure below. The ‘𝜏’ symbols in the figure stand for the Kendall rank correlation coefficient while the ‘r’ symbols stand for the Pearson correlation coefficient. I used the Kendall correlation because it can capture nonlinear divergences between the measures and the Pearson coefficient is the familiar linear correlation. The “evenly spaced” scores aren’t totally in agreement with the scores from the ordinal models, but they are close enough that I doubt that prior research that used the “evenly spaced” scores to measure quality was mislead by this choice.
Correlations between quality measures show that the different approaches to measuring quality are quite similar. “Evenly spaced” uses the weighted sum of the ORES scores with handpicked coefficients [0,1,2,3,4,5]. Lower values of Kendall’s 𝜏, a nonparametric rank correlation statistic, compared to Pearson’s 𝑟 suggest nonlinear differences between the weighted sum and the other measures.
Conclusions
Measuring article quality in one continuous dimension is a valuable tool for studying the peer production of information goods because it provides granularity and is amenable to statistical analysis. Prior approaches extended ORES article quality prediction into a continuous measure under the “evenly spaced” assumption. I used ordinal regression models to transform the ORES predictions into a continuous measure of quality that is interpretable as a probability distribution over article quality levels, provides an account of its own uncertainty and does not assume that quality levels are “evenly spaced.” Calibrating the models to the chosen unit of analysis improves accuracy for research applications. I recommend that future work adopt this approach when article quality is an independent variable in a statistical analysis.
My paper also has a number of other tidbits about the uncertainty of different quality measures, the importance of feedback between measurement and knowledge in the scientific process and demonstrates model calibration.
A preprint of the paper is available here. The paper has been accepted to OpenSym 2021 and will be presented at the virtual conference on September 17th. A video of the presentation is available here. A dataverse repository containing code and data from the project is available here.
The number of unique commenters who commented on subreddits in March 2020, for subreddits that had at least 1 comment in the each of the previous 23 months. The “SR” communities are those we drew our interview sample from.
When it comes to online communities, we often assume that bigger is better. Large communities can create robust interactions, have access to broad and extensive body of experiences, and provide many opportunities for connections. As a result, small communities are often thought as failed attempts to build big ones. In reality, most online communities are very small and most small communities remain small throughout their lives. If growth and a large number of members are so advantageous, why do small communities not only exist but persist in their smallness?
In a recent research study, we investigated why individuals participate in these persistently small online communities by interviewing twenty participants of small subreddits on Reddit. We asked people about their motivations and explicitly tried to get them to compare their experiences in small subreddits with their experience in larger subreddits. Below we present three of the main things that we discovered through analyzing our conversations.
Size of consistently active subreddits over time (i.e., those with at least one comment per month from April 2018 to March 2020). Subreddits are grouped by their size in April 2018. Lines represent the median size each month, and ribbons show the first and third quartiles.
Informational niches
First, we found that participants saw their small communities as unique spaces for information and interaction. Frequently, small communities are narrower versions or direct offshoots of larger communities. For example, the r/python community is about the programming language Python while the r/learnpython community is a smaller community explicitly for newcomers to the language.
By being in a smaller, more specific community, our participants described being able to better anticipate the content, audience, and norms: a specific type of content, people who cared about the narrow topic just like them, and expectations of how to behave online. For example, one participant said:
[…] I can probably make a safe assumption that people there more often than not know what they’re talking about. I’ll definitely be much more specific and not try to water questions down with like, my broader scheme of things—I can get as technical as possible, right? If I were to ask like the same question over at [the larger parent community], I might want to give a little bit background on what I’m trying to do, why I’m trying to do it, you know, other things that I’m using, but [in small community], I can just be like, hey, look, I’m trying to use this algorithm for this one thing. Why should I? Or should I not do it for this?
Curating online experiences
More broadly, participants explained their participation in these small communities as part of an ongoing strategy of curating their online experience. Participants described a complex ecosystem of interrelated communities that the small communities sat within, and how the small communities gave them the ability to select very specific topics, decide who to interact with, and manage content consumption.
In this sense, small communities give individuals a semblance of control on the internet. Given the scale of the internet—and a widespread sense of malaise with online hate, toxicity, and harassment—it is possible that controlling the online experience is more important to users than ever. Because of their small size, these small communities were largely free of the vandals and trolls that plague large online communities, and several participants described their online communities as special spaces to get away from the negativity on the rest of the internet.
Relationships
Finally, one surprise from our research was what we didn’t find. Previous research led us to predict that people would participate in small communities because they would make it easier to develop friendships with other people. Our participants described being interested in the personal experiences of other group members, but not in building individual relationships with them.
Conclusions
Our research shows that small online communities play an important and underappreciated role. At the individual level, online communities help people to have control over their experiences, curating a set of content and users that is predictable and navigable. At the platform level, small communities seem to have a symbiotic relationship with large communities. By breaking up broader topical niches, small communities likely help to keep a larger set of users engaged.
We hope that this paper will encourage others to take seriously the role of small online communities. They are qualitatively different from large communities, and more empirical and theoretical research is needed in order to understand how communities of different sizes operate and interact in community ecosystems.
A preprint of the paper is available here. We’re excited that this paper has been accepted to CSCW2021 and will be published in the Proceedings of the ACM on Human-Computer Interaction and presented at the conference in November. If you have any questions about this research, please feel free to reach out to one of the authors: Sohyeon Hwang or Jeremy Foote.
It’s Ph.D. application season and the Community Data Science Collective is recruiting! As always, we are looking for talented people to join our research group. Applying to one of the Ph.D. programs that the CDSC faculty members are affiliated with is a great way to do that.
This post provides a very brief run-down on the CDSC, the different universities and Ph.D. programs we’re affiliated with, and what we’re looking for when we review Ph.D. applications. It’s close to the deadline for some of our programs, but we hope this post will still be useful to prospective applicants now and in the future.
Group photo of the collective at a recent virtual retreat.
What are these different Ph.D. programs? Why would I choose one over the other?
This year the group includes four faculty principal investigators (PIs) who are actively recruiting PhD students: Aaron Shaw (Northwestern University), Benjamin Mako Hill and Sayamindu Dasgupta (University of Washington in Seattle), and Jeremy Foote (Purdue University). Each of these PIs advise Ph.D. students in Ph.D. programs at their respective universities. Our programs are each described below.
Although we often work together on research and serve as co-advisors to students in each others’ projects, each faculty person has specific areas of expertise and interests. The reasons you might choose to apply to one Ph.D. program or to work with a specific faculty member could include factors like your previous training, career goals, and the alignment of your specific research interests with our respective skills.
At the same time, a great thing about the CDSC is that we all collaborate and regularly co-advise students across our respective campuses, so the choice to apply to or attend one program does not prevent you from accessing the expertise of our whole group. But please keep in mind that our different Ph.D. programs have different application deadlines, requirements, and procedures!
Who is actively recruiting this year?
Given the disruptions and uncertainties associated with the COVID19 pandemic, the faculty PIs are more constrained in terms of whether and how they can accept new students this year. If you are interested in applying to any of the programs, we strongly encourage you to reach out the specific faculty in that program before submitting an application.
Aaron Shaw is an Associate Professor in the Department of Communication Studies at Northwestern. In terms of Ph.D. programs, Aaron’s primary affiliations are with the Media, Technology and Society (MTS) and the Technology and Social Behavior (TSB) Ph.D. programs. Aaron also has a courtesy appointment in the Sociology Department at Northwestern, but he has not directly supervised any Ph.D. advisees in that department (yet). Aaron’s current research projects focus on comparative analysis of the organization of peer production communities and social computing projects, participation inequalities in online communities, and empirical research methods.
Jeremy Foote
Jeremy Foote is an Assistant Professor at the Brian Lamb School of Communication at Purdue University. He is affiliated with the Organizational Communication and Media, Technology, and Society programs. Jeremy’s current research focuses on how individuals decide when and in what ways to contribute to online communities, how communities change the people who participate in them, and how both of those processes can help us to understand which things become popular and influential. Most of his research is done using data science methods and agent-based simulations.
What do you look for in Ph.D. applicants?
There’s no easy or singular answer to this. In general, we look for curious, intelligent people driven to develop original research projects that advance scientific and practical understanding of topics that intersect with any of our collective research interests.
To get an idea of the interests and experiences present in the group, read our respective bios and CVs (follow the links above to our personal websites). Specific skills that we and our students tend to use on a regular basis include experience consuming and producing social science and/or social computing (human-computer interaction) research; applied statistics and statistical computing, various empirical research methods, social theory and cultural studies, and more.
Formal qualifications that speak to similar skills and show up in your resume, transcripts, or work history are great, but we are much more interested in your capacity to learn, think, write, analyze, and/or code effectively than in your credentials, test scores, grades, or previous affiliations. It’s graduate school and we do not expect you to show up knowing how to do all the things already.
Intellectual creativity, persistence, and a willingness to acquire new skills and problem-solve matter a lot. We think doctoral education is less about executing a task that someone else hands you and more about learning how to identify a new, important problem; develop an appropriate approach to solving it; and explain all of the above and why it matters so that other people can learn from you in the future. Evidence that you can or at least want to do these things is critical. Indications that you can also play well with others and would make a generous, friendly colleague are really important too.
All of this is to say, we do not have any one trait or skill set we look for in prospective students. We strive to be inclusive along every possible dimension. Each person who has joined our group has contributed unique skills and experiences as well as their own personal interests. We want our future students and colleagues to do the same.
Now what?
Still not sure whether or how your interests might fit with the group? Still have questions? Still reading and just don’t want to stop? Follow the links above for more information. Feel free to send at least one of us an email. We are happy to try to answer your questions and always eager to chat.
Debian is one of the oldest, largest, and most influential peer production communities and has produced an operating system used by millions for over the last three decades. DebConf is that community’s annual meeting. This year, the Community Data Science Collective was out in force at Debian’s virtual conference to present several Debian-focused research projects that we’ve been working on.
First, Wm Salt Hale presented work from his master thesis project on “Resilience in FLOSS: Do founder decisions impact development activity after crisis events?” His work tried to understand the social dynamics behind organizational resilience among free software projects based on what Salt calls “founder decisions.” He did so by estimating the relationship between changes in developer activity after security bugs and testing several theories about how this relationship might vary between permissive and copyleft licensed software packages.
