Shuguang Han

University of Pittsburgh | Pitt · Information Science and Technology

In this paper, we report the results of our participation in the TREC-COVID challenge. To meet the challenge of building a search engine for rapidly evolving biomedical collection, we propose a simple yet effective weighted hierarchical rank fusion approach, that ensembles together 102 runs from (a) lexical and semantic retrieval systems, (b) pre-t...

This paper describes a machine learning algorithm for document (re)ranking, in which queries and documents are firstly encoded using BERT [1], and on top of that a learning-to-rank (LTR) model constructed with TF-Ranking (TFR) [2] is applied to further optimize the ranking performance. This approach is proved to be effective in a public MS MARCO be...

Web crawlers spend significant resources to maintain freshness of their crawled data. This paper describes the optimization of resources to ensure that product prices shown in ads in a context of a shopping sponsored search service are synchronized with current merchant prices. We are able to use the predictability of price changes to build a machi...

Purpose The purpose of this paper is to predict news intent by exploring contextual and temporal features directly mined from a general search engine query log. Design/methodology/approach First, a ground-truth data set with correctly marked news and non-news queries was built. Second, a detailed analysis of the search goals and topics distribut...

With the wide adoption of social media in recent years, researchers on social information access are gaining more interests on applying various of social interactions (e.g., friendship, bookmarking, tagging) for satisfying people’s information needs. In this chapter, we focus on methods and technologies to boost information retrieval performance ba...

In this study, we examined what sources laypeople would select (i.e., visit and adopt) to resolve their health-related information needs, and how different health conditions affect the selection. Twenty-four college students participated in this user study, where they were asked to search for two separate health issues respectively: multiple sclero...

Human multi-robot interaction exploits both the human operator's high-level decision-making skills and the robotic agents’ vigorous computing and motion abilities. While controlling multi-robot teams, an operator's attention must constantly shift between individual robots to maintain sufficient situation awareness. To conserve an operator's attenti...

In this study, we examined what sources laypeople would select (i.e., visit and adopt) to resolve their health-related information needs, and how different health conditions affect the selection. Twenty- four college students participated in this user study, where they were asked to search for two separate health issues respectively: multiple scler...

Purpose The purpose of this paper is to explore different tagging behaviors between Chinese and Americans by analyzing the movie tags, and explore the feasibility of applying cultural differences to tag recommendations. Design/methodology/approach This paper introduced hypotheses based on several well-established psychology theories, and tested...

Keyphrase provides highly-summative information that can be effectively used for understanding, organizing and retrieving text content. Though previous studies have provided many workable solutions for automated keyphrase extraction, they commonly divided the to-be-summarized content into multiple text chunks, then ranked and selected the most mean...

Keyphrase provides highly-summative information that can be effectively used for understanding, organizing and retrieving text content. Though previous studies have provided many workable solutions for automated keyphrase extraction, they commonly divided the to-be-summarized content into multiple text chunks, then ranked and selected the most mean...

Recent studies have witnessed an increasing popularity of cross-device web search, in which a user resumes a previously started search task from one device to a later session on another. The complexity of this novel search mode, mainly due to the involvement of interruptions and multiple devices, makes users conduct new types of search behaviors an...

When using search engines, people often issue multiple related queries to accomplish a complex search task. A simple query-task structure may not fully capture the complexity of query relations since people may divide a task into multiple subtasks. As a result, this paper applies a three-level hierarchical structure with query, goal and mission - a...

Various e-learning systems that provide electronic textbooks are gathering large amounts of student reading interactions. This data can potentially be used to model student knowledge acquisition. However, reading activity is often overlooked in canonical student modeling. Prior studies modeling learning from reading either estimate knowledge at the...

Exploring the topic hierarchy of a research field can help us better recognize its intellectual structure. This paper proposes a new method to automatically discover the topic hierarchy, in which the keyword network is constructed to represent topics and their relations, and then decomposed hierarchically into shells using the K-core decomposition...

Knowledge learning is recognized as an important component in people's search process. Existing studies on this topic usually measure the knowledge growth before and after a search. However, there still lacks a fine-grained understanding of users' knowledge change patterns within a search process and users' adoption of different sources for learnin...

Parsing the semantic structure of a web page is a key component of web information extraction. Successful extraction algorithms usually require large-scale training and evaluation datasets, which are difficult to acquire. Recently, crowdsourcing has proven to be an effective method of collecting large-scale training data in domains that do not requ...

Recent research shows that Collaborative Information Retrieval (CIR), in which two or more users collaborate on the same search task, has become increasingly popular. The presence of both search and collaboration behaviors makes CIR a complex search format, which further drives a critical need to understand CIR's search context. The contextual supp...

Recent research shows that Collaborative Information Retrieval (CIR), in which two or more users collaborate on the same search task, has become increasingly popular. The presence of both search and collaboration behaviors makes CIR a complex search format, which further drives a critical need to understand CIR's search context. The contextual supp...

Human multi-robot control is a complex process: an operator’s attention constantly shifts among various tasks to maintain the necessary awareness of a given situation, such as exploring environments and locating targets simultaneously. To minimize the laborious monitoring, if a robot can self-reflect its needs for interaction and alert an operator...

The wide adoption of smartphones eliminates the time and location barriers for people's daily information access, but also limits users' information exploration activities due to the small mobile screen size. Thus, cross-device web search, where people initialize information needs on one device but complete them on another device, is frequently obs...

Mobile devices enable people to look for information at the moment when their information needs are triggered. While experiencing complex information needs that require multiple search sessions, users may utilize desktop computers to fulfill information needs started on mobile devices. Under the context of mobileto-desktop web search, this article...

Open user modeling has been perceived as an important mechanism to enhance the effectiveness of personalization. However, several studies have reported that open and editable user models can harm the performance of personalized search systems. This paper re-examines the value of open and editable user models in the context of personalized search. W...

Open user modeling has been perceived as an important mechanism to enhance the effectiveness of personalization. However, several studies have reported that open and editable user models can harm the performance of personalized search systems. This paper re-examines the value of open and editable user models in the context of personalized search. W...

People search is an important topic in information retrieval. Many previous studies on this topic employed social networks to boost search performance by incorporating either local network features (e.g. the common connections between the querying user and candidates in social networks), or global network features (e.g. the PageRank), or both. Howe...

Online surveys are becoming more popular as a means of information gathering in both academia and industry because of their relatively low cost and delivery. However, there are increasing debates on data quality in online surveys. We present a novel survey prototyping tool that integrates embedded learning resources to facilitate the survey prototy...

Compared to desktop interfaces, touch-enabled mobile devices allow richer user interaction with actions such as drag, pinch-in, pinch-out, and swipe. While these actions have been already used to improve the ranking of search results or lists of recommendations, in this paper we focus on understanding how these actions are used in exploration tasks...

Past analysis has considered query reformulation primarily from the perspective of individual Web searches. Findings from a recent study suggest ways that collaboration during the search process influences how users generate new terms for query reformulation.

Investigations of search processes that involve complex interactions, such as collaborative search processes, are important research topics. Previous approaches of directly applying individual search process models into collaborative settings have proven to be problematic. In this paper, we proposed an innovative approach to model collaborative sea...

Many online communities face the challenge of incorporating a stable influx of newcomers into the community. Research on socialization in offline organizations suggest that newcomers who join an organization with a cohort of other newcomers are more likely to succeed in the organization. We have studied the effect of socializing a cohort of newcome...

Establishing a respectful and well-functional program committee (PC) consisting of capable PC members is one of the most important tasks for conference organizers. However, little research has been done for automatic recommendation of PC candidates. PC member finding is a complex task, which could be influenced by many factors such as the candidate...

People search is an active research topic in recent years. Related works includes expert finding, collaborator recommendation, link prediction and social matching. However, the diverse objectives and exploratory nature of those tasks make it difficult to develop a flexible method for people search that works for every task. In this project, we deve...

Information seeking process is an important topic in information seeking behavior research. Both qualitative and empirical methods have been adopted in analyzing information seeking processes, with major focus on uncovering the latent search tactics behind user behaviors. Most of the existing works require defining search tactics in advance and cod...

Research collaboration can bring in different perspectives and generate more productive results. However, finding an appropriate collaborator can be difficult due to the lacking of sufficient information. Link prediction is a related technique for collaborator discovery; but its focus has been mostly on the core authors who have relatively more pub...

We propose a new aspect of evaluating scientific articles: crucialness, which refers to the state of articles being not only useful, but also scarce (difficult to be found or identified by scientists). Compared with the popularity-based metrics, crucialness may be a better metric in helping scientists' information seeking and use because it identif...

Research in offline and online communities has identified feedback from existing members as an important factor in encouraging participation by new members. However, many online communities suffer from a lack of interaction among newcomers and existing members. There has been less research on how this interaction can be encouraged and facilitated....

Collaboration in the information seeking and retrieval environment is common, particularly when the search task is complex and exploratory. Multiple factors such as contextual features and task type can affect users' query behavior. This paper presents a study investigating the effects of collaboration and task types on users' query behavior. The s...

Collaboration in Web search can be characterized as implicit or ex-plicit in terms of intent, and synchronous or asynchronous in terms of concur-rency. Different collaboration style may greatly affect search actions. This pa-per presents a user study aiming to compare search processes in three different conditions: pair of users working on the same...

Investigations on search processes can either be at macro-level or micro-level. The macro-level investigation focuses on establishing theoretical models while micro-level investigation focuses on the user actions. In this paper, we propose using search tactics as means of examining search processes in collaborative exploratory search, which can be...

We propose a method to dynamically estimate the utility of documents in a search session by modeling the users' browsing behaviors and novelty. The method can be applied to evaluate query reformulations in a search session.

This paper presents a user study aiming to investigate the query reformulation in collaborative Web search. 7 pairs of participants were recruited and each pair worked as a team on two collaborative exploratory Web search tasks. Through the log analysis, we compared possible sources for participants to draw query terms from. The results show that b...

Current search systems are designed to find relevant articles, especially topically relevant ones, but the notion of relevance largely depends on search tasks. We study the specific task that scientists are searching for worth-reading articles beneficial for their research. Our study finds: users' perception of relevance and preference of reading a...

This paper presents a user study aiming to investigate search processes in collaborative exploratory Web search. Our analysis of search processes focuses on the distribution and transition of user search actions captured in a collaborative web search system called CollabSearch. The results show that a large proportion of users' actions in collabora...

This paper presents a user study aiming to investigate search processes in collaborative exploratory Web search. Our analysis of search processes focuses on the distribution and transition of user search actions captured in a collaborative web search system called CollabSearch. The results show that a large proportion of users' actions in collabora...

In this paper, we introduce our approaches for TREC 2011 session track. Our approaches focus on combining different query language models to model information needs in a search session. In RL1 stage, we build ad hoc retrieval system using sequential dependence model (SDM) on current query. In RL2 stage, we build query language models by combining S...

Modern scientific researches are facing two kinds of problems: how to select proper research themes, how to get related experts and works. Expert search and hotspot detecting are two methods used broadly to settle these problems. Expert search can help resolving the problems of expertise retrieval, expert evaluation, collaborator choosing and so on...

Purpose This paper aims to provide an overview for the main project details of the China Academic Digital Library (CADL) with focused introduction on China Academic Library and Information System (CALIS), China Academic Digital Library and Information System (CADLIS), China‐America Digital Academic Library (CADAL) and China Academic Humanities and...