Effective content moderation in online communities is often a delicate balance between maintaining content quality and fostering user participation. In this paper, we introduce post guidance, a novel approach to community moderation that proactively guides users' contributions using rules that trigger interventions as users draft a post to be submitted. For instance, rules can surface messages to users, prevent post submissions, or flag posted content for review. This uniquely community-specific, proactive, and user-centric approach can increase adherence to rules without imposing additional burdens on moderators. We evaluate a version of Post Guidance implemented on Reddit, which enables the creation of rules based on both post content and account characteristics. Specifically, we conduct a large randomized experiment, capturing activity from 97,616 posters in 33 subreddits over 63 days. We find that Post Guidance (1) increased the number of "successful posts" (posts not removed after 72 hours), (2) decreased moderators' workload in terms of manually-reviewed reports, (3) increased contribution quality, as measured by community engagement, and (4) had no impact on posters' own subsequent activity, within communities adopting the feature. Post Guidance on Reddit was similarly effective for community veterans and newcomers, with greater benefits in communities that used the feature more extensively. Our findings indicate that post guidance represents a transformative approach to content moderation, embodying a paradigm that can be easily adapted to other platforms to improve online communities across the Web.

Online photo collections are often presented along with numeric data, such as views, likes, or comments. Treemaps are ideal for visualizing such collections, as they present numeric values using rectangular blocks, within which photos can be presented. Despite abundant research showing that photo treemaps and similar space-filling approaches are useful and appealing for users, understanding of the ideal parameters for constructing these representations remains limited. To address this, we contribute a series of experiments targeted at identifying design parameters for building photo treemaps. Our first study explores the number of photos presented at each level in the treemap, finding that using fewer photos makes visualizations more searchable and preferable to users. A second study examines the tradeoff between sizing photos according to the numeric values and presenting them in a more familiar layout with fixed aspect ratios. These results inform a third study, in which a prototype was used to probe the preferences of active Flickr users for using treemaps for navigating photo collections.

Participants in social media systems must balance many considerations when choosing what to share and with whom. Sharing with others invites certain risks, as well as potential benefits; achieving the right balance is even more critical when sharing photos, which can be particularly engaging, but potentially compromising. In this paper, we examine photo-sharing decisions as an interaction between high-level user preferences and specific features of the images being shared. Our analysis combines insights from a 96-user survey with metadata from 10.4M photos to develop a model integrating these perspectives to predict permissions settings for uploaded photos. We discuss implications, including how such a model can be applied to provide online sharing experiences that are more safe, more scalable, and more satisfying.

Crowdsourcing is a common strategy for collecting the “gold standard” labels required for many natural language applications. Crowdworkers differ in their responses for many reasons, but existing approaches often treat disagreements as "noise" to be removed through filtering or aggregation. In this paper, we introduce the workflow design pattern of crowd parting: separating workers based on shared patterns in responses to a crowdsourcing task. We illustrate this idea using an automated clustering-based method to identify divergent, but valid, worker interpretations in crowdsourced entity annotations collected over two distinct corpora -- Wikipedia articles and Tweets. We demonstrate how the intermediate-level view provide by crowd-parting analysis provides insight into sources of disagreement not easily gleaned from viewing either individual annotation sets or aggregated results. We discuss several concrete applications for how this approach could be applied directly to improving the quality and efficiency of crowdsourced annotation tasks.

Abstract Browsing is a fundamental aspect of exploratory information‐seeking. Associative browsing represents a common and intuitive set of exploratory strategies in which users step iteratively from familiar to novel bits of information. In this paper, we examine associative browsing as a strategy for bottom‐up exploration of large, heterogeneous networks. We present Refinery, an interactive visualization system informed by guidelines for associative browsing drawn from literature on exploratory information‐seeking. These guidelines motivate Refinery's query model, which allows users to simply and expressively construct queries using heterogeneous sets of nodes. This system computes degree‐of‐interest scores for associated content using a fast, random‐walk algorithm. Refinery visualizes query nodes within a subgraph of results, providing explanatory context, facilitating serendipitous discovery, and stimulating continued exploration. A study of 12 academic researchers using Refinery to browse publication data demonstrates how the system enables discovery of valuable new content, even within existing areas of expertise.

Visual methods for supporting the characterization, comparison, and classification of large networks remain an open challenge. Ideally, such techniques should surface useful structural features -- such as effective diameter, small-world properties, and structural holes -- not always apparent from either summary statistics or typical network visualizations. In this paper, we present GraphPrism, a technique for visually summarizing arbitrarily large graphs through combinations of 'facets', each corresponding to a single node- or edge-specific metric (e.g., transitivity). We describe a generalized approach for constructing facets by calculating distributions of graph metrics over increasingly large local neighborhoods and representing these as a stacked multi-scale histogram. Evaluation with paper prototypes shows that, with minimal training, static GraphPrism diagrams can aid network analysis experts in performing basic analysis tasks with network data. Finally, we contribute the design of an interactive system using linked selection between GraphPrism overviews and node-link detail views. Using a case study of data from a co-authorship network, we illustrate how GraphPrism facilitates interactive exploration of network data.

Online social networks have become indispensable tools for information sharing, but existing 'all-or-nothing' models for sharing have made it difficult for users to target information to specific parts of their networks. In this paper, we study Google+, which enables users to selectively share content with specific 'Circles' of people. Through a combination of log analysis with surveys and interviews, we investigate how active users organize and select audiences for shared content. We find that these users frequently engaged in selective sharing, creating circles to manage content across particular life facets, ties of varying strength, and interest-based groups. Motivations to share spanned personal and informational reasons, and users frequently weighed ''limiting' factors (e.g. privacy, relevance, and social norms) against the desire to reach a large audience. Our work identifies implications for the design of selective sharing mechanisms in social networks.

This paper presents a research project on the design of a cross-channel information management tool for knowledge workers: we focus on IT services professionals in a large enterprise who work in multiple ad hoc task forces. Through three rounds of investigation, we characterized their work practices and needs, specified their requirements for a cross-channel information management tool, and designed and evaluated a prototype to address these needs. We found that these workers shared the problem of managing information across multiple channels, requiring better support for aggregating, filtering, and organizing this information. We report the requirements elicited and the prototypes built during the design process.

Information overload is a growing threat to the productivity of today's knowledge workers, who need to keep track of multiple streams of information from various sources. RSS feed readers are a popular choice for syndicating information streams, but current tools tend to contribute to the overload problem instead of solving it. We introduce FeedWinnower, an enhanced feed aggregator that helps readers to filter feed items by four facets (topic, people, source, and time), thus facilitating feed triage. The combination of the four facets provides a powerful way for users to slice and dice their personal feeds. In addition, we present a formative evaluation of the prototype conducted with 15 knowledge workers in two different organizations.

Twitter streams are on overload: active users receive hundreds of items per day, and existing interfaces force us to march through a chronologically-ordered morass to find tweets of interest. We present an approach to organizing a user's own feed into coherently clustered trending topics for more directed exploration. Our Twitter client, called Eddi, groups tweets in a user's feed into topics mentioned explicitly or implicitly, which users can then browse for items of interest. To implement this topic clustering, we have developed a novel algorithm for discovering topics in short status updates powered by linguistic syntactic transformation and callouts to a search engine. An algorithm evaluation reveals that search engine callouts outperform other approaches when they employ simple syntactic transformation and backoff strategies. Active Twitter users evaluated Eddi and found it to be a more efficient and enjoyable way to browse an overwhelming status update feed than the standard chronological interface.