Category: Papers

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Effects of Algorithmic Flagging on Fairness: Quasi-experimental Evidence from Wikipedia

Many online platforms are adopting machine learning as a tool to maintain order and high quality information in the face of massive influxes of of user generated content. Of course, machine learning algorithms can be inaccurate, biased or unfair. How do signals from machine learning predictions shape the fairness of online content moderation? How can we measure an algorithmic flagging system’s effects?

In our paper published at CSCW 2021, I (Nate TeBlunthuis) together with Benjamin Mako Hill and Aaron Halfaker analyzed the RCFilters system: an add-on to Wikipedia that highlights and filters edits that a machine learning algorithm called ORES identifies as likely to be damaging to Wikipedia. This system has been deployed on large Wikipedia language editions and is similar to other algorithmic flagging systems that are becoming increasingly widespread. Our work measures the causal effect of being flagged in the RCFilters user interface.

Screenshot of Wikipedia edit metadata on Special:RecentChanges with RCFilters enabled. Highlighted edits with a colored circle to the left side of other metadata are flagged by ORES. Different circle and highlight colors (white, yellow, orange, and red in the figure) correspond to different levels of confidence that the edit is damaging. RCFilters does not specifically flag edits by new accounts or unregistered editors, but does support filtering changes by editor types.

Our work takes advantage of the fact that RCFilters, like many algorithmic flagging systems, create discontinuities in the relationship between the probability that a moderator should take action and whether a moderator actually does. This happens because the output of machine learning systems like ORES is typically a continuous score (in RCFilters, an estimated probability that a Wikipedia edit is damaging), while the flags (in RCFilters, the yellow, orange, or red highlights) are either on or off and are triggered when the score crosses some arbitrary threshold. As a result, edits slightly above the threshold are both more visible to moderators and appear more likely to be damaging than edits slightly below. Even though edits on either side of the threshold have virtually the same likelihood of truly being damaging, the flagged edits are substantially more likely to be reverted. This fact lets us use a method called regression discontinuity to make causal estimates of the effect of being flagged in RCFilters.

Charts showing the probability that an edit will be reverted as function of ORES scores in the neighborhood of the discontinuous threshold that triggers the RCfilters flag. The jump in the increase in reversion chances is larger for registered editors compared to unregistered editors at both thresholds.

To understand how this system may effect the fairness of Wikipedia moderation, we estimate the effects of flagging on edits on different groups of editors. Comparing the magnitude of these estimates lets us measure how flagging is associated with several different definitions of fairness. Surprisingly, we found evidence that these flags improved fairness for categories of editors that have been widely perceived as troublesome—particularly unregistered (anonymous) editors. This occurred because flagging has a much stronger effect on edits by the registered than on edits by the unregistered.

We believe that our results are driven by the fact algorithmic flags are especially helpful for finding damage that can’t be easily detected otherwise. Wikipedia moderators can see the editor’s registration status in the recent changes, watchlists, and edit history. Because unregistered editors are often troublesome, Wikipedia moderators’ attention is often focused on their contributions, with or without algorithmic flags. Algorithmic flags make damage by registered editors (in addition to unregistered editors) much more detectable to moderators and so help moderators focus on damage overall, not just damage by suspicious editors. As a result, the algorithmic flagging system decreases the bias that moderators have against unregistered editors.

This finding is particularly surprising because the ORES algorithm we analyzed was itself demonstrably biased against unregistered editors (i.e., the algorithm tended to greatly overestimate the probability that edits by these editors were damaging). Despite the fact that the algorithms were biased, their introduction could still lead to less biased outcomes overall.

Our work shows that although it is important to design predictive algorithms to not have such biases, it is equally important to study fairness at the level of the broader sociotechnical system. Since we first published a preprint of our paper, a followup piece by Leijie Wang and Haiyi Zhu replicated much of our work and showed that differences between different Wikipedia communities may be another important factor driving the effect of the system. Overall, this work suggests that social signals and social context can interact with algorithmic signals and together these can influence behavior in important and unexpected ways.

The full citation for the paper is: TeBlunthuis, Nathan, Benjamin Mako Hill, and Aaron Halfaker. 2021. “Effects of Algorithmic Flagging on Fairness: Quasi-Experimental Evidence from Wikipedia.” Proceedings of the ACM on Human-Computer Interaction 5 (CSCW): 56:1-56:27. https://doi.org/10.1145/3449130.

We have also released replication materials for the paper, including all the data and code used to conduct the analysis and compile the paper itself.

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Literature on Inequality and Discrimination in the Gig Economy

Inequality and discrimination in the labor market is a persistent and sometimes devastating problem for job seekers. Increasingly, labor is moving to online platforms, but labor inequality and discrimination research often overlooks work that happens on such platforms. Do research findings from traditional labor contexts generalize to the online realm? We have reason to think perhaps not, since entering the online labor market requires specific technical infrastructure and skills (as we showed in this paper). Besides, hiring processes for online platforms look significantly different: these systems use computational structures to organize labor at a scale that exceeds any hiring operation in the traditional labor market.

To understand what research on patterns of inequality and discrimination in the gig economy is out there and to identify remaining puzzles, I (Floor) systematically gathered, analyzed, and synthesized studies on this topic. The result is a paper recently published in New Media & Society.

I took a systematic approach in order to capture all the different strands of inquiry across various academic fields. These different strands might use different methods and even different language but, crucially, still describe similar phenomena. For this review, Siying Luo (research assistant on this project) and I gathered literature from five academic databases covering multiple disciplines. By sifting through many journal articles and conference proceedings, we identified 39 studies of participation and success in the online labor market.

Most research focuses on individual-level resources and biases as a source of unequal participation, rather than the role of the platform.

Three approaches

I found three approaches to the study of inequality and discrimination in the gig economy. All address distinct research questions drawing on different methods and framing (see the table below for an overview).

Approach 1 asks who does and who does not engage in online labor. This strand of research takes into account the voices of both those who have pursued such labor and those who have not. Five studies take this approach, of which three draw on national survey data and two others examine participation among a specific population (such as older adults).

Approach 2 asks who online contractors are. Some of this research describes the sociodemographic composition of contractors by surveying them or by analyzing digital trace data. Other studies focus on labor outcomes, identifying who among those that pursue online labor actually land jobs and generate an income. You might imagine a study asking whether male contractors make more money on an online platform than female contractors do.

Approach 3 asks what social biases exist in the hiring process, both on the side of individual users making hiring decisions and the algorithms powering the online labor platforms. Studies taking this approach tend to rely on experiments that test the impact of some manipulation in the contractor’s sociodemographic background on an outcome, such as whether they get featured by the platform or whether they get hired.

This is a table that gives an overview of the three approaches identified in the scoping review. For every approach, it lists the central research question, the method, and the number of papers.

Extended pipeline of online participation inequalities

In addition to identifying these three approaches, I map the outcomes variables of all studies across an extended version of the so-called pipeline of participation inequalities (as coined and tested in this paper). This model breaks down the steps one needs to take before being able to contribute online, presenting them in the form of a pipeline. Studying online participation as stages of the pipeline allows for the identification of barriers since it reveals the spots where people face obstacles and drop out before fully participating. Mapping the literature on inequality and discrimination in the gig economy across stages of a pipeline proved helpful in understanding and visualizing what parts of the process of becoming an online contractor have been studied and what parts require more attention.

I extended the pipeline of participation inequalities to fit the process of participating in the gig economy. This form of online participation does not only require having the appropriate access and skills to participate, but also requires garnering attention and getting hired. The extended pipeline model has eleven stages: from having heard of a platform to receiving payment as well as reviews and ratings for having performed a job. The figure below shows a visualization of the pipeline with the number of studies that study an outcome variable associated with each stage.

This image is a drawing of a pipeline made up of various pieces. Inside each piece, it indicates the corresponding stage of the process of becoming an online contractor. It also has numbers of how many studies examined each pipeline stage. At the end of the pipeline, there is two water droplets that represent labor outcomes (payments and reviews/ratings).
The extended pipeline of participation inequalities, specific to the process of becoming an online contractor, with the number of studies that examined each stage

When mapping the studies across the pipeline, we find that two stages have been studied much more than others. Prior literature primarily examines whether individuals who pursue work online are getting hired and receiving a payment. In contrast, the literature in this scoping review hardly examined earlier stages of the pipeline.

So, what should we take away?

After systematically gathering and analyzing the literature on inequality and discrimination in the online labor market, I want to highlight three takeaways.

One: Most of the research focuses on individual-level resources and biases as a source of unequal participation. This scoping review points to a need for future research to examine the specific role of the platform in facilitating inequality and discrimination.

Two: The literature thus far has primarily focused on behaviors at the end of the pipeline of participation inequalities (i.e., having been hired and received payment). Studying earlier stages is important as it might explain patterns of success in later stages. In addition, such studies are also worthwhile inquiries in their own right. Insights into who meets these conditions of participation and desired labor outcomes are valuable, for example, in designing policy interventions.

Three: Hardly any research looks at participation across multiple stages of the pipeline. Considering multiple stages in one study is important to identify the moments that individuals face obstacles and how sociodemographic factors relate to making it from one stage to the next.

For more details, please find the full paper here.

Floor Fiers is PhD candidate at Northwestern University in the Media, Technology, and Society program. They received support and advice from other members of the collective. Most notably, Siying Luo contributed greatly to this project as a research assistant.

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Mapping the many pathways of learning in online communities

Thousands of widely used online communities are designed to promote learning. Although some rely on formal educational approaches like lesson plans, curriculum, and tests, many of the most successful learning communities online are structured as what scholars call a community of practice (CoP). In CoPs, members mentor and apprentice with each other (both formally and informally) while working toward a common interest or goal. For example, the Scratch online community is a CoP where millions of young people share and collaborate on programming projects.

Despite an enormous amount of attention paid to online CoPs, there is still a lot of disagreement about the best ways to promote learning in them. One source of disagreement stems from the fact that participants in CoPs are learning a number of different kinds of things and designers are often trying to support many types of learning at once. In a new paper that I’ve published—and that I will be presenting at CSCW this week—I conduct quantitative analyses on data from Scratch to show that there is a complex set of learning pathways at play in CoPs like Scratch. Types of participation that are associated with some important kinds of learning are often unrelated to, or even negatively associated with, other important types of learning outcomes. 

The Scratch online community (left) and an example of a programming project in Scratch (right). 

So what exactly are people learning in CoPs?  We dug into the CoP literature and identified three major types of learning outcomes: 

  • Learning about the domain, which refers to learning knowledge and skills for the core tasks necessary for achieving the explicit goal in the community. In Scratch, this is learning to code.
  • Learning about the community, which means the development of identity as a community member, forming relationships, affinities, and a sense of belonging. In Scratch, this involves learning to interact with others users and developing an identity as a community member.
  • Learning about the practice, which means adopting community specific values, such as the style of contribution that will be accepted and appreciated by its members. In Scratch, this means becoming a valued and respected contributor to the community.

So what types of participation might contribute to learning in a CoP?  We identified several different types of newcomers’ participation that may support learning:

  • Contribution to core tasks which involves direct work towards the community’s explicit goal. In Scratch, this often involves making original programming projects.
  • Engagement with practice proxies which involves observing and participating in others’ work practices. In Scratch, this might mean remixing others’ projects by making changes and building on existing code. 
  • Feedback exchange with community members about their contributions. In Scratch, this often involves writing comments on others’ projects.
  • Social bonding with community members. In Scratch, this can involve “friending” others, which allows a user to follow others’ projects and updates.
A visual representation of our study design.

We conducted a quantitative analysis on how the different types of newcomer participation contribute to the different learning outcomes. In other words, we tested for the presence/absence and the direction of the relationships (shown as the orange arrows) between each of the learning outcomes on the top of the figure and each of the types of newcomer participation on the bottom. To conduct these tests, we used data from Scratch to construct a user level dataset with proxy measures for each type of learning and type of newcomer participation as well as a series of important control variables. All the technical details about the measures and models are in the paper. 

Overall, what we found was a series of complex trade-offs that suggest the kinds of things that support one type of learning frequently do not support others. For example, we found that contribution to core tasks as a newcomer is positively associated with learning about the domain in the long term, but negatively associated with learning about the community and its practices. We found that engagement with practice proxies as a newcomer is negatively associated with long-term learning about the domain and the community. Engaging in feedback exchange and social bonding as a newcomer, on the other hand, are positively associated with learning about the community and its practice.

Our findings indicate that there are no easy solutions: different types of newcomer participation provide varying support for different learning outcomes. What is productive for some types of learning outcomes can be unhelpful for others, and vice versa. For example, although social features like feedback mechanisms and systems for creating social bonds may not be a primary focus of many learning systems, they could be implemented to help users develop a sense of belonging in the community and learn about community specific values. At the same time, while contributing to core tasks may help with domain learning, direct contribution may often be too difficult and might discourage newcomers from staying in the community and learn about its values.

The paper and this blog post are collaborative work between Ruijia “Regina” Cheng and Benjamin Mako Hill. The paper is being published this month(open access) in the Proceedings of the ACM on Human-Computer Interaction The full citation for this paper is: Ruijia Cheng and Benjamin Mako Hill. 2022. Many Destinations, Many Pathways: A Quantitative Analysis of Legitimate Peripheral Participation in Scratch. Proc. ACM Hum.-Comput. Interact. 6, CSCW2, Article 381 (November 2022), 26 pages https://doi.org/10.1145/3555106

The paper is also available as an arXiv preprint and in the ACM Digital Library. The paper is being presented several times at the Virtual CSCW conference taking place in November 2022. Both Regina and Mako are happy to answer questions over email, in the comments on this blog post, or at the one remaining presentation slot at the CSCW conference on November 16th at 8-9pm Pacific Time. 

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How social context explains why some online communities engage contributors better than others

More than a billion people visit Wikipedia each month and millions have contributed as volunteers. Although Wikipedia exists in 300+ language editions, more than 90% of Wikipedia language editions have fewer than one hundred thousand articles. Many small editions are in languages spoken by small numbers of people, but the relationship between the size of a Wikipedia language edition and that language’s number of speakers—or even the number of viewers of the Wikipedia language editions—varies enormously. Why do some Wikipedias engage more potential contributors than others? We attempted to answer this question in a study of three Indian language Wikipedias that will be published and presented at the ACM Conference on Human Factors in Computing (CHI 2022).

To conduct our study, we selected 3 Wikipedia language communities that correspond to the official languages of 3 neighboring states of India: Marathi (MR) from the state of Maharashtra, Kannada (KN) from the state of Karnataka, and Malayalam (ML) from the state of Kerala (see the map in right panel of the figure above). While the three projects share goals, technological infrastructure, and a similar set of challenges, Malayalam Wikipedia’s community engaged its language speakers in contributing to Wikipedia at a much higher rate than the others. The graph above (left panel) shows that although MR Wikipedia has twice as many viewers as ML Wikipedia, ML has more than double the number of articles on MR.

Our study focused on identifying differentiating factors between the three Wikipedias that could explain these differences. Through a grounded theory analysis of interviews with 18 community participants from the three projects, we identified two broad explanations of a “positive participation cycle” in Malayalam Wikipedia and a “negative participation cycle” in Marathi and Kannada Wikipedias. 

As the first step of our study, we conducted semistructured interviews with active participants of all three projects to understand their personal experiences and motivation; their perceptions of dynamics, challenges, and goals within their primary language community; and their perceptions of other language Wikipedia. 

We found that MR and KN contributors experience more day-to-day barriers to participation than ML, and that these barriers hinder contributors’ day-to-day activity and impede engagement. For example, both MR and KN members reported a large number of content disputes that they felt reduced their desire to contribute.

But why do some Wikipedias like MR or KN have more day-to-day barriers to contribution like content disputes and low social support than others? Our interviews pointed to a series of higher-level explanations. For example, our interviewees reported important differences in the norms and rules used within each community as well as higher levels of territoriality and concentrated power structures in MR and KN.

Once again, though: why do the MR and KN Wikipedias have these issues with territoriality and centralized authority structures? Here we identify a third, even higher-level set of differences in the social and cultural contexts of the three language-speaking communities. For example, MR and KN community members attributed low engagement to broad cultural attitudes toward volunteerism and differences in their language community’s engagement with free software and free culture.

The two flow charts above visualize the explanatory mapping of divergent feedback loops we describe.  The top part of the figure illustrates how the relatively supportive macro-level social environment in Kerala led to a larger group of potential contributors to ML as well as a chain reaction of processes that led to a Wikipedia better able to engage potential contributors. The process is an example of a positive feedback cycle. The second, bottom part of the figure shows the parallel, negative feedback cycle that emerged in MR and KN Wikipedias. In these settings, features of the macro-level social environment led to a reliance on a relatively small group of people for community leadership and governance. This led, in turn, to barriers to entry that reduced contributions. 

One final difference between the three Wikipedias was the role that paid labor from NGOs played. Because the MR and KN Wikipedias struggled to recruit and engage volunteers, NGOs and foundations deployed financial resources to support the development of content in Marathi and Kannada, but not in ML to the same degree. Our work suggested this tended to further concentrate power among a small group of paid editors in ways that aggravated the meso-level community struggles. This is shown in the red box in the second (bottom) row of the figure.

The results from our study provide a conceptual framework for understanding how the embeddedness of social computing systems within particular social and cultural contexts shape various aspects of the systems. We found that experience with participatory governance and free/open-source software in the Malayalam community supported high engagement of contributors. Counterintuitively, we found that financial resources intended to increase participation in the Marathi and Kannada communities hindered the growth of these communities. Our findings underscore the importance of social and cultural context in the trajectories of peer production communities. These contextual factors help explain patterns of knowledge inequity and engagement on the internet. 

Please refer to the preprint of the paper for more details on the study and our design suggestions for localized peer production projects. We’re excited that this paper has been accepted to CHI 2022 and received the Best Paper Honorable Mention Award! It will be published in the Proceedings of the ACM on Human-Computer Interaction and presented at the conference in May. The full citation for this paper is:

Sejal Khatri, Aaron Shaw, Sayamindu Dasgupta, and Benjamin Mako Hill. 2022. The social embeddedness of peer production: A comparative qualitative analysis of three Indian language Wikipedia editions. In CHI Conference on Human Factors in Computing Systems (CHI ’22), April 29-May 5, 2022, New Orleans, LA, USA. ACM, New York, NY, USA, 18 pages. https://doi.org/10.1145/3491102.3501832

If you have any questions about this research, please feel free to reach out to one of the authors: Sejal Khatri, Benjamin Mako Hill, Sayamindu Dasgupta, and Aaron Shaw. 

Attending the conference in New Orleans? Come attend our live presentation on May 3 at 3 pm at the CHI program venue, where you can discuss the paper with all the authors. 

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How does Interest-driven Participation Shape Computational Learning in Online Communities?

Online communities are frequently described as promising sites for computing education. Advocates of online communities as contexts for learning argue that they can help novices learn concrete programming skills through self-directed and interest-driven work. Of course, it is not always clear how well this plays out in practice—especially when it comes to learning challenging programming concepts. We sought to understand this process through a mixed-method case study of the Scratch online community that will be published and presented at the ACM Conference on Human Factors in Computing (CHI 2022) in several weeks.

Scratch is the largest online interest-driven programming community for novices. In Scratch, users can create programming projects using the visual-block based Scratch programming language. Scratch users can choose to share their projects—and many do—so that they can be seen, interacted with, and remixed by other Scratch community members. Our study focused on understanding how Scratch users learn to program with data structures (i.e., variables and lists)—a challenging programming concept for novices—by using community-produced learning resources such as discussion threads and curated project examples. Through a qualitative analysis on Scratch forum discussion threads, we identified a social feedback loop where participation in the community raises the visibility of some particular ways of using variables and lists in ways that shaped the nature and diversity of community-produced learning resources. In a follow-up quantitative analysis on a large collection of Scratch projects, we find statistical support for this social process. 

A program made by a stack of Scratch programming blocks. From the top to bottom: ``when clicked,'' ``forever,'' ``if touching Bat? then,'' ``change score by -1.''
A Scratch project code of a score counter in a game. 

As the first step of our study, we collected and qualitatively analyzed 400 discussion threads about variables and lists in the Scratch Q&A forums. Our key finding was that Scratch users use specific, concrete examples to teach each other about variables and lists. These examples are commonly framed in terms of elements in the projects that they are making, often specific to games.

For instance, we observed users teach each other how to make a score counter in a game using variables. In another example, we saw users sharing tips on creating an item inventory in a game using lists. As a result of this focus on specific game elements, user-generated examples and tutorials are often framed in the specifics of these game-making scenarios. For example, a lot of sample Scratch code on variables and lists were from games with popular elements like scores and inventories. While these community-produced learning resources offers valuable concrete examples, not everybody is interested in making games. We some some evidence that users who are not interested in making games involving scores and inventories were less likely to get effective support when they sought to learn about variables. We argue that repeated over time, this dynamic can lead to a social feedback loop where reliance on community-generated resources can place innovative forms of creative coding at a disadvantage compared to historically common forms.

This diagram illustrates the hypothetical social feedback loop that we constructed based on our findings in Study 1. The diagram starts with the box of ``Stage 1'' on the left, and the text that explains Stage 1 says: ``learners create artifacts with Use Case A.'' There is a right-going arrow pointing from Stage 1 to the box of ``Stage 2'' on the right and the text on the arrow says: ``learners turn to the community for help or inspiration.'' The text that explains Study 2 says: ``Community cumulates learning resources framed around Use Case A.'' Above these is a left-going arrow that points from Stage 2 back to Stage 1, forming the loop. The text on the arrow says: ``Subsequent learners get exposed to resources about Use Case A.'' Underneath the entire loop there is an down-going arrow pointing to a box of ``Outcome.'' The text that explains Outcome says: ``Use Case A becomes archetypal. Other innovative use cases become less common.''
Our proposed hypothetical social feedback loop of how community-generated resources may constrain innovative computational participation. 

The graph here is a visualization of the social feedback loop theory that we proposed. Stage 1 suggests that, in an online interest-driven learning community, some specific applications of a concept (“Use Case A”) will be more popular than others. This might be due to random chance or any number of reasons. When seeking community support, learners will tend to ask questions framed specifically around Use Case A and use community resources framed in terms of the same use case. Stage 2 shows the results of this process. As learners receive support, they produce new artifacts with Use Case A that can serve as learning resources for others. Then, learners in the future can use these learning resources, becoming even more likely to create the same specific application. The outcome of the feedback loop is that, as certain applications of a concept become more popular over time, the community’s learning resources are increasingly focused on the same applications.

We tested our social feedback loop theory using 5 years of Scratch data including 241,634 projects created by 75,911 users. We tested both the mechanism and the outcome of the loop from multiple angles in terms of three hypotheses that we believe will be true if our the feedback loop we describe is shaping behavior:

  1. More projects involving variables and lists will be games over time.
  2. The type of project elements that users make with variables and lists (we defined it as the names that they gave to variables and lists) will be more homogenous.
  3. Users who have been exposed to popular variable and list names will be more likely to use those names in their own projects. We found at least some support for all of our hypotheses.

Our results provide broad (if imperfect) support for our social feedback loop theory. For example, the graph below illustrates one of our findings: users who have been exposed to popular list names (solid line) will be more likely to use (in other words, less likely to never use) popular names in their projects, compared to users who have never downloaded projects with popular list names (dashed line). 

This figure is a line plot that illustrates the curves from the survival analysis for lists. The x-axis is ``Number of shared de novo projects w/ list.'' The labels are ``0'', ``10'', ``20'', and ``30'' from left to right. The y-axis is ``Proportion of users who have never used popular variable names.'' The labels are ``0.00'', ``0.25'', ``0.50'', ``0.75'', and ``1.00'' from bottom to top. There are two lines. The dashed line represents users who never downloaded projects with popular variable names. The solid line represents users who has downloaded projects with popular variable names.The solid line starts at 1 on x-axis and approximately 0.75 on the y-axis. The solid line descends in a convex shape and when it reaches 10 on the x-axis, it is at around 0.25 on the y-axis. The line keeps descending, reaches around 0.05 on the y-axis when it is at 25 on the x-axis, and stays at 0.05 for the rest of the x-axis. The dashed line is significantly higher than the solid line and stays above it the entire graph. The dashed line starts at 1 on x-axis and approximately 0.88 on the y-axis. The dashed line descends in a convex shape that is less steep than the solid line, and when it reaches 10 on the x-axis, it is at around 0.50 on the y-axis. The line keeps descending, reaches around 0.24 on the y-axis when it is at 25 on the x-axis, and stays at 0.24 for the rest of the x-axis.
Plots from our cox proportional survival analysis on the difference between users who have previously downloaded projects with popular list names versus those who have never done so. 

The results from our study describe an important trade-off that designers of online communities in computational learning need to be aware of. On the one hand, learners can learn advanced computational concepts by building their own explanation and understanding on specific use cases that are popular in the community. On the other, such learning can be superficial and not conceptual or generalizable: learners’ preference for peer-generated learning resources around specific interests can restrict the exploration of broader and more innovative uses, which can potentially limit sources of inspiration, pose barriers to broadening participation, and confine learners’ understanding of general concepts. We conclude our paper suggesting several design strategies that might be effective in countering this effect.

Please refer to the preprint of the paper for more details on the study and our design suggestions for future online interest-driven learning communities. We’re excited that this paper has been accepted to CHI 2022 and received the Best Paper Honorable Mention Award! It will be published in the Proceedings of the ACM on Human-Computer Interaction and presented at the conference in May. The full citation for this paper is:

Ruijia Cheng, Sayamindu Dasgupta, and Benjamin Mako Hill. 2022. How Interest-Driven Content Creation Shapes Opportunities for Informal Learning in Scratch: A Case Study on Novices’ Use of Data Structures. In CHI Conference on Human Factors in Computing Systems (CHI ’22), April 29-May 5, 2022, New Orleans, LA, USA. ACM, New York, NY, USA, 16 pages. https://doi.org/10.1145/3491102.3502124

If you have any questions about this research, please feel free to reach out to one of the authors: Ruijia “Regina” Cheng, Sayamindu Dasgupta, and Benjamin Mako Hill.

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Fool’s gold? The perils of using online survey samples to study online behavior

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.

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The Hidden Costs of Requiring Accounts

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.

If you do not have access to the paywalled journal, please check out this pre-print or get in touch with us. We have also released replication materials for the paper, including all the data and code used to conduct the analysis and compile the paper itself.

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Measuring Wikipedia Article Quality in One Continuous Dimension

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.

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Why do people participate in small online communities?

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.

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Do generous attitudes underlie contributions to user-generated content?

User-generated content on the Internet provides the basis for some of the most popular websites, such as Wikipedia, crowdsourced question-and-answer sites like Stack Overflow, video-sharing sites like YouTube, and social media platforms like Reddit. Much (or in some cases all) of the content on these sites is created by unpaid volunteers, who invest substantial time and effort to produce high quality information resources. So are these volunteers and content contributors more generous in general than people who don’t contribute their time, knowledge, or information online?

We (Floor Fiers, Aaron Shaw, and Eszter Hargittai) consider this question in a recent paper published in The Journal of Quantitative Description: Digital Media (JQD:DM). The publication of this particularly is exciting because it pursues a new angle on these questions, and also because it’s part of the inaugural issue of JQD:DM, a new open-access venue for research that seeks to advance descriptive (as opposed to analytic or causal) knowledge about digital media.

The study uses data from a national survey of U.S. adult internet users that includes questions about many kinds of online contribution activities, various demographic and background attributes, as well as a dictator game to measure generosity. In the dictator game, each participant has an opportunity to make an anonymous donation of some unanticipated funds to another participant in the study. Prior experimental research across the social sciences has used dictator games, but no studies we know of had compared dictator game donations with online content contributions.

Sharing content. GotCredit via flickr.

Overall, we find that people who contribute some kind of content online exhibit more generosity in the dictator game. More specifically, we find that people producing any type of user-generated content tend to donate more in the dictator game than those who do not produce any such content. We also disaggregate the analysis by type of content contribution and find that donating in the dictator game only correlates with content contribution for those who write reviews, upload public videos, pose or answer questions, and contribute to encyclopedic knowledge collections.

So, generous attitudes and behaviors may help explain contributions to some types of user-generated content, but not others. This implies that user-generated content is not a homogeneous activity, since variations exist between different types of content contribution.

The (open access!) paper has many more details, so we hope you’ll download, read, and cite it. Please feel free to leave a comment below too.

Paper Citation: Fiers, Floor, Aaron Shaw, and Eszter Hargittai. 2021. “Generous Attitudes and Online Participation”. Journal of Quantitative Description: Digital Media 1 (April). https://doi.org/10.51685/jqd.2021.008.