Automated Essay Scoring automates the grading process of essays, providing a great advantage for improving the writing proficiency of students. While holistic essay scoring research is prevalent, a noticeable gap exists in scoring essays for specific quality traits. In this work, we focus on the relevance trait, which measures the ability of the student to stay on-topic throughout the entire essay. We propose a novel approach for graded relevance scoring of written essays that employs dense retrieval encoders. Dense representations of essays at different relevance levels then form clusters in the embeddings space, such that their centroids are potentially separate enough to effectively represent their relevance levels. We hence use the simple 1-Nearest-Neighbor classification over those centroids to determine the relevance level of an unseen essay. As an effective unsupervised dense encoder, we leverage Contriever, which is pre-trained with contrastive learning and demonstrated comparable performance to supervised dense retrieval models. We tested our approach on both task-specific (i.e., training and testing on same task) and cross-task (i.e., testing on unseen task) scenarios using the widely used ASAP++ dataset. Our method establishes a new state-of-the-art performance in the task-specific scenario, while its extension for the cross-task scenario exhibited a performance that is on par with the state-of-the-art model for that scenario. We also analyzed the performance of our approach in a more practical few-shot scenario, showing that it can significantly reduce the labeling cost while sacrificing only 10% of its effectiveness.

The recent advances in natural language processing have yielded many exciting developments in text analysis and language understanding models; however, these models can also be used to track people, bringing severe privacy concerns. In this work, we investigate what individuals can do to avoid being detected by those models while using social media platforms. We ground our investigation in two exposure-risky tasks, stance detection and geotagging. We explore a variety of simple techniques for modifying text, such as inserting typos in salient words, paraphrasing, and adding dummy social media posts. Our experiments show that the performance of BERT-based models fine-tuned for stance detection decreases significantly due to typos, but it is not affected by paraphrasing. Moreover, we find that typos have minimal impact on state-of-the-art geotagging models due to their increased reliance on social networks; however, we show that users can deceive those models by interacting with different users, reducing their performance by almost 50%.

Over the past years, notable progress has been made towards fighting misinformation spread over social media, encouraging the development of many fact-checking systems. However, systems that operate over Arabic content are scarce. In this work, we bridge this gap by proposing Tahaqqaq (Verify), an Arabic real-time system that helps users verify claims over Twitter with several functionalities, such as identifying check-worthy claims, estimating credibility of users in terms of spreading fake news, and finding authoritative accounts. Tahaqqaq has a friendly online Web interface that supports various real-time user scenarios. In the same breath, we enable public access to Tahaqqaq services through a handy RESTful API. Finally, in terms of performance, multiple components of Tahaqqaq outperform the state-of-the-art models on Arabic datasets.

A large body of research work has proposed verification techniques for rumors spreading in social media that mainly relied on subjective evidence, e.g., propagation networks or user interactions. Alternatively, in this work, we introduce the task of authority finding in social media, in which we aim to find authorities, for given rumors spreading specifically in Twitter, who can help verify them by providing exclusive/convincing evidence that supports or denies those rumors. We release the first test collection for Authority FINding in Arabic Twitter (AuFIN). The collection comprises 150 rumors (expressed in tweets) associated with a total of 1,044 authority accounts and a user collection of 395,231 Twitter accounts (members of 1,192,284 unique Twitter lists). Moreover, we propose a hybrid model that employs pre-trained language models and combines lexical, semantic, and network signals to find authorities. Our experiments show that the textual representation of users is insufficient, and incorporating the Twitter network features improved the recall of authorities by 34%. Moreover, semantic ranking is inferior to the lexical and network-based ranking in terms of precision, but superior in terms of recall. Therefore, combining both the semantic and network-based ranking achieved the best overall performance achieving a precision of 0.413 and 0.213 at depth 1 and 5 respectively. We show that rumor expansion by exploiting Knowledge Bases improves the recall of authorities by up to 15%. Furthermore, we find that SOTA models for topic expert finding perform poorly on finding authorities. Finally, drawing upon our experiments, we discuss failure factors and make recommendations for future research directions in addressing this task.

Several fake claims are commonly repeated over time, especially on social media. To identify such previous claims, the verified claim retrieval task was studied, where, for a given input claim, the goal is to find previously-verified claims that are relevant to it. However, this view assumes that each claim was already verified, which may not be true for all claims in the real-world scenario. In this work, we introduce the Verified Claim Checking problem over Twitter, in which the relevant verified claims are retrieved only if the input claim was indeed previously-verified, thus saving computation time. We address the problem by proposing SpotVC, an end-to-end approach consisting of two stages, namely a filter and a reranker. The proposed filter achieved an average F1 of 0.81 while significantly reducing computation time. Moreover, the proposed reranker outperformed the state-of-the-art models on two public datasets and provided on-par performance on a third one. Overall, our proposed system exhibits an effective operational balance in the trade-off between efficiency and effectiveness for the real-world scenario.

While utilizing Twitter data for crisis management is of interest to different response authorities, a critical challenge that hinders the utilization of such data is the scarcity of automated tools that extract geolocation information. The limited focus on Location Mention Recognition (LMR) in tweets, specifically, is attributed to the lack of a standard dataset that enables research in LMR. To bridge this gap, we present IDRISI-RE, a large-scale human-labeled LMR dataset comprising around 20.5k tweets. The annotated location mentions within the tweets are also assigned location types (e.g., country, city, street, etc.). IDRISI-RE contains tweets from 19 disaster events of diverse types (e.g., flood and earthquake) covering a wide geographical area of 22 English-speaking countries. Additionally, IDRISI-RE contains about 56.6k automatically-labeled tweets that we offer as a silver dataset. To highlight the superiority of IDRISI-RE over past efforts, we present rigorous analyses on reliability, consistency, coverage, diversity, and generalizability. Furthermore, we benchmark IDRISI-RE using a representative set of LMR models to provide the community with baselines for future work. Our extensive empirical analysis shows the promising generalizability of IDRISI-RE compared to existing datasets. We show that models trained on IDRISI-RE better tackle domain shifts and are less susceptible to change in geographical areas.

In this work, we tackle the problem of machine reading comprehension (MRC) on the Holy Qur’an to address the lack of Arabic datasets and systems for this important task. We construct QRCD as the first Qur’anic Reading Comprehension Dataset, composed of 1,337 question-passage-answer triplets for 1,093 question-passage pairs, of which 14% are multi-answer questions. We then introduce CLassical-AraBERT (CL-AraBERT for short), a new AraBERT-based pre-trained model, which is further pre-trained on about 1.0B-word Classical Arabic (CA) dataset, to complement the Modern Standard Arabic (MSA) resources used in pre-training the initial model, and make it a better fit for the task. Finally, we leverage cross-lingual transfer learning from MSA to CA, and fine-tune CL-AraBERT as a reader using two MSA-based MRC datasets followed by our QRCD dataset to constitute the first (to the best of our knowledge) MRC system on the Holy Qur’an. To evaluate our system, we introduce Partial Average Precision (pAP) as an adapted version of the traditional rank-based Average Precision measure, which integrates partial matching in the evaluation over multi-answer and single-answer MSA questions. Adopting two experimental evaluation setups (hold-out and cross validation (CV)), we empirically show that the fine-tuned CL-AraBERT reader model significantly outperforms the baseline fine-tuned AraBERT reader model by 6.12 and 3.75 points in pAP scores, in the hold-out and CV setups, respectively. To promote further research on this task and other related tasks on Qur’an and Classical Arabic text, we make both the QRCD dataset and the pre-trained CL-AraBERT model publicly available.

Abstract Web search is commonly used by fact checking systems as a source of evidence for claim verification. In this work, we demonstrate that the task of retrieving pages useful for fact checking, called evidential pages, is indeed different from the task of retrieving topically relevant pages that are typically optimized by search engines; thus, it should be handled differently. We conduct a comprehensive study on the performance of retrieving evidential pages over a test collection we developed for the task of re‐ranking Web pages by usefulness for fact‐checking. Results show that pages (retrieved by a commercial search engine) that are topically relevant to a claim are not always useful for verifying it, and that the engine's performance in retrieving evidential pages is weakly correlated with retrieval of topically relevant pages. Additionally, we identify types of evidence in evidential pages and some linguistic cues that can help predict page usefulness. Moreover, preliminary experiments show that a retrieval model leveraging those cues has a higher performance compared to the search engine. Finally, we show that existing systems have a long way to go to support effective fact checking. To that end, our work provides insights to guide design of better future systems for the task.

News background linking is the problem of finding online resources that can provide valuable context and background information to help the reader comprehend a given news article. While the problem has recently attracted several researchers, however, the notion of background relevance is not well-studied and it requires better understanding to ensure effective system performance. In this paper, we conduct a qualitative analysis on a sample of 25 query news articles and 152 of their corresponding background articles, in addition to 50 of non-background ones. The goal of the study is to shed some light on the relationship between the query articles and the background articles, and provide informative insights for developing more effective background retrieval models. For instance, our analysis shows that event-driven query articles are, on average, harder to process than others, hence they should be handled differently. It also shows that discussing subtopics in detail and adding new informative topics are both essential factors for highly-relevant background articles. Moreover, it shows that a high lexical similarity between a query article and a background one is neither sufficient nor necessary.

The scarcity of Arabic test collections has long hindered information retrieval (IR) research over the Arabic Web. In this work, we present ArTest, the first large-scale test collection designed for the evaluation of ad-hoc search over the Arabic Web. ArTest uses ArabicWeb16, a collection of around 150M Arabic Web pages as the document collection, and includes 50 topics, 10,529 relevance judgments, and (more importantly) a rationale behind each judgment. To our knowledge, this is also the first IR test collection that includes rationales of primary assessors (i.e., topic developers) for their relevance judgments, exhibiting a useful resource for understanding the relevance phenomena. Finally, ArTest is made publicly-available for the research community.

Many top-k document retrieval strategies have been proposed based on the WAND and MaxScore heuristics and yet, from recent work, it is surprisingly difficult to identify the "fastest" strategy. This becomes even more challenging when considering various retrieval criteria, like different ranking models and values of k. In this paper, we conduct the first extensive comparison between ten effective strategies, many of which were never compared before to our knowledge, examining their efficiency under five representative ranking models. Based on a careful analysis of the comparison, we propose LazyBM, a remarkably simple retrieval strategy that bridges the gap between the best performing WAND-based and MaxScore-based approaches. Empirically, LazyBM considerably outperforms all of the considered strategies across ranking models, values of k, and index configurations under both mean and tail query latency.

Because it is expensive to construct test collections for Cranfield-based evaluation of information retrieval systems, a variety of lower-cost methods have been proposed. The reliability of these methods is often validated by measuring rank correlation (e.g., Kendall's tau) between known system rankings on the full test collection vs. observed system rankings on the lower-cost one. However, existing rank correlation measures do not consider the statistical significance of score differences between systems in the observed rankings. To address this, we propose two statistical-significance-aware rank correlation measures, one of which is a head-weighted version of the other. We first show empirical differences between our proposed measures and existing ones. We then compare the measures while benchmarking four system evaluation methods: pooling, crowdsourcing, evaluation with incomplete judgments, and automatic system ranking. We show that use of our measures can lead to different experimental conclusions regarding reliability of alternative low-cost evaluation methods.

Even though Web search engines play an important role in finding documents relevant to user queries, there is little to no attention given to how they perform in terms of usefulness for fact-checking claims. In this paper, we introduce a new research problem that addresses the ability of fact-checking systems to distinguish Web search results that are useful in discovering the veracity of claims from the ones that are not.We also propose a re-ranking method to improve ranking of search results for fact-checking. To evaluate our proposed method, we conducted a preliminary study for which we have developed a test collection that includes 22 claims and 20 manually-annotated Web search results for each. Our experiments show that the proposed method outperforms the baseline represented by the original ranking of search results. The contributions this improvement brings to real-world applications is two-fold: it will help human fact-checkers find useful documents for their task faster, and it will help automated fact-checking systems by pointing out which documents are useful and which are not.

While peer-agreement and gold checks are well-established methods for ensuring quality in crowdsourced data collection, we explore a relatively new direction for quality control: estimating work quality directly from workers’ behavioral traces collected during annotation. We propose three behavior-based models to predict label correctness and worker accuracy, then further apply model predictions to label aggregation and optimization of label collection. As part of this work, we collect and share a new Mechanical Turk dataset of behavioral signals judging the relevance of search results. Results show that behavioral data can be effectively used to predict work quality, which could be especially useful with single labeling or in a cold start scenario in which individuals’ prior work history is unavailable. We further show improvement in label aggregation and reducing labeling cost while ensuring data quality.

While crowdsourcing offers a low-cost, scalable way to collect relevance judgments, lack of transparency with remote crowd work has limited understanding about the quality of collected judgments. In prior work, we showed a variety of benefits from asking crowd workers to provide \em rationales for each relevance judgment \citemcdonnell2016relevant. In this work, we scale up our rationale-based judging design to assess its reliability on the 2014 TREC Web Track, collecting roughly 25K crowd judgments for 5K document-topic pairs. We also study having crowd judges perform topic-focused judging, rather than across topics, finding this improves quality. Overall, we show that crowd judgments can be used to reliably rank IR systems for evaluation. We further explore the potential of rationales to shed new light on reasons for judging disagreement between experts and crowd workers. Our qualitative and quantitative analysis distinguishes subjective vs.\ objective forms of disagreement, as well as the relative importance of each disagreement cause, and we present a new taxonomy for organizing the different types of disagreement we observe. We show that many crowd disagreements seem valid and plausible, with disagreement in many cases due to judging errors by the original TREC assessors. We also share our WebCrowd25k dataset, including: (1) crowd judgments with rationales, and (2) taxonomy category labels for each judging disagreement analyzed.

This paper presents LA3 , a scalable distributed system for graph analytics. LA3 couples a vertex-based programming model with a highly optimized linear algebra-based engine. It translates any vertex-centric program into an iteratively executed sparse matrix-vector multiplication (SpMV). To reduce communication and enhance scalability, the adjacency matrix representing an input graph is partitioned into locality-aware 2D tiles distributed across multiple processes. Alongside, three major optimizations are incorporated to preclude redundant computations and minimize communication. First, the link-based structure of the input graph is exploited to classify vertices into different types. Afterwards, vertices of special types are factored out of the main loop of the graph application to avoid superfluous computations. We refer to this novel optimization as computation filtering. Second, a communication filtering mechanism is involved to optimize for the high sparsity of the input matrix due to power-law distributions, common in real-world graphs. This optimization ensures that each process receives only the messages that pertain to non-zero entries in its tiles, substantially reducing communication traffic since most tiles are highly sparse. Lastly, a pseudo-asynchronous computation and communication optimization is proposed, whereby processes progress and communicate asynchronously, consume messages as soon as they become available, and block otherwise. We implemented and extensively tested LA3 on private and public clouds. Results show that LA3 outperforms six related state-of-the-art and popular distributed graph analytics systems by an average of 10X.

When collecting subjective human ratings of items, it can be difficult to measure and enforce data quality due to task subjectivity and lack of insight into how judges’ arrive at each rating decision. To address this, we propose requiring judges to provide a specific type of rationale underlying each rating decision. We evaluate this approach in the domain of Information Retrieval, where human judges rate the relevance of Webpages to search queries. Cost-benefit analysis over 10,000 judgments collected on Mechanical Turk suggests a win-win: experienced crowd workers provide rationales with almost no increase in task completion time while providing a multitude of further benefits, including more reliable judgments and greater transparency for evaluating both human raters and their judgments. Further benefits include reduced need for expert gold, the opportunity for dual-supervision from ratings and rationales, and added value from the rationales themselves.

Research on event detection in Twitter is often obstructed by the lack of publicly-available evaluation mechanisms such as test collections; this problem is more severe when considering the scarcity of them in languages other than English. In this paper, we present EveTAR, the first publicly-available test collection for event detection in Arabic tweets. The collection includes a crawl of 590M Arabic tweets posted in a month period and covers 66 significant events (in 8 different categories) for which more than 134k relevance judgments were gathered using crowdsourcing with high average inter-annotator agreement (Kappa value of 0.6). We demonstrate the usability of the collection by evaluating 3 state-of-the-art event detection algorithms. The collection is also designed to support other retrieval tasks, as we show in our experiments with ad-hoc search systems.

Web crawls provide valuable snapshots of the Web which enable a wide variety of research, be it distributional analysis to characterize Web properties or use of language, content analysis in social science, or Information Retrieval (IR) research to develop and evaluate effective search algorithms. While many English-centric Web crawls exist, existing public Arabic Web crawls are quite limited, limiting research and development. To remedy this, we present ArabicWeb16, a new public Web crawl of roughly 150M Arabic Web pages with significant coverage of dialectal Arabic as well as Modern Standard Arabic. For IR researchers, we expect ArabicWeb16 to support various research areas: ad-hoc search, question answering, filtering, cross-dialect search, dialect detection, entity search, blog search, and spam detection. Combined use with a separate Arabic Twitter dataset we are also collecting may provide further value.

Over the past years, Twitter has earned a growing reputation as a hub for communication, and events advertisement and tracking. However, several recent research studies have shown that Twitter users (and microblogging platforms' users in general) are increasingly posting microblogs containing questions seeking answers from their readers. To help those users answer or route their questions, the problem of question identification in tweets has been studied over English tweets; up to our knowledge, no study has attempted it over Arabic (not to mention dialectal Arabic) tweets.

Previous research has shown that features based on term proximity are important for effective retrieval. However, they incur substantial costs in terms of larger inverted indexes and slower query execution times as compared to term-based features. This paper explores whether term proximity features based on approximate term positions are as effective as those based on exact term positions. We introduce the novel notion of approximate positional indexes based on dividing documents into coarse-grained buckets and recording term positions with respect to those buckets. We propose different approaches to defining the buckets and compactly encoding bucket ids. In the context of linear ranking functions, experimental results show that features based on approximate term positions are able to achieve effectiveness comparable to exact term positions, but with smaller indexes and faster query evaluation.

Test collections are the primary drivers of progress in information retrieval. They provide yardsticks for assessing the effectiveness of ranking functions in an automatic, rapid, and repeatable fashion and serve as training data for learning to rank models. However, manual construction of test collections tends to be slow, labor-intensive, and expensive. This paper examines the feasibility of constructing web search test collections in a completely unsupervised manner given only a large web corpus as input. Within our proposed framework, anchor text extracted from the web graph is treated as a pseudo query log from which pseudo queries are sampled. For each pseudo query, a set of relevant and non-relevant documents are selected using a variety of web-specific features, including spam and aggregated anchor text weights. The automatically mined queries and judgments form a pseudo test collection that can be used for training ranking functions. Experiments carried out on TREC web track data show that learning to rank models trained using pseudo test collections outperform an unsupervised ranking function and are statistically indistinguishable from a model trained using manual judgments, demonstrating the usefulness of our approach in extracting reasonable quality training data "for free".

This work explores the problem of cross-lingual pairwise similarity, where the task is to extract similar pairs of documents across two different languages. Solutions to this problem are of general interest for text mining in the multilingual context and have specific applications in statistical machine translation. Our approach takes advantage of cross-language information retrieval (CLIR) techniques to project feature vectors from one language into another, and then uses locality-sensitive hashing (LSH) to extract similar pairs. We show that effective cross-lingual pairwise similarity requires working with similarity thresholds that are much lower than in typical monolingual applications, making the problem quite challenging. We present a parallel, scalable MapReduce implementation of the sort-based sliding window algorithm, which is compared to a brute-force approach on German and English Wikipedia collections. Our central finding can be summarized as "no free lunch": there is no single optimal solution. Instead, we characterize effectiveness-efficiency tradeoffs in the solution space, which can guide the developer to locate a desirable operating point based on application- and resource-specific constraints.

Abstract Informal communications media pose new challenges for information‐systems design, but the nature of informal interaction offers new opportunities as well. This paper describes NetLens‐E‐mail, a system designed to support exploration of the content‐actor network in large e‐mail collections. Unique features of NetLens‐E‐mail include close coupling of orientation, specification, restriction, and expansion, and introduction and incorporation of a novel capability for iterative projection between content and actor networks within the same collection. Scenarios are presented to illustrate the intended employment of NetLens‐E‐mail, and design walkthroughs with two domain experts provide an initial basis for assessment of the suitability of the design by scholars and analysts.

Summative evaluation methods for supervised adaptive topic tracking systems convolve the effect of system decisions on present utility with the effect on future utility. This paper describes a new formative evaluation approach that focuses on future utility for use in the design stage of adaptive systems. Topic model quality is assessed at a predefined set of points using a fixed document set to enhance comparability. Experiments using a vector-space topic tracking system illustrate the utility of this approach to formative evaluation.