Ulrich Norbisrath

Ordinary search engine users carrying out complex search tasks

Web search engines have become the dominant tools for finding information on the Internet. Owing to their popularity, users of all educational backgrounds and professions use them for a wide range of tasks, from simple look-up to rather complex information-seeking needs. This paper presents the results of a study that investigates the behavioural search characteristics of ordinary Web search engines users. The aim of the study was to investigate (1) what makes complex search tasks distinct from simple search tasks and whether it is possible to find simple measures for describing their complexity, and (2) whether successful searchers show different search behaviours than unsuccessful searchers and whether good searchers can be identified via simple measures. The study included 56 ordinary Web users who carried out a set of 12 search tasks using current commercial search engines. Their behaviour was logged with the Search-Logger tool. The results confirm that the behaviour in the case of complex search tasks has significantly different inherent characteristics than in the case of simple search tasks. This can be proven by using simple measures such as task time, number of queries, or number of browser tabs used. We also observed that it is difficult to distinguish successful from unsuccessful search behaviour simply by using these measures. The implications of our findings for search engine vendors are discussed. The results of this study with a sample of ordinary users are insofar unique as they are valid for a wider population while most studies in the field are usually done using convenience samples such as university students.

Search-logger analyzing exploratory search tasks

In this paper, we focus on a specific class of search cases: exploratory search tasks. To describe and quantify their complexity, we present a new methodology and corresponding tools to evaluate the user behavior when carrying out exploratory search tasks. These tools consist of a client called Search-Logger, and a server side database with frontend and an analysis environment. The client is a plug-in for Firefox web browsers. The assembly of the Search-Logger tools can be used to carry out user studies for search tasks independent of a laboratory environment. It collects implicit user information by logging a number of significant user events. Explicit information is gathered via user feedback in the form of questionnaires before and after each search task. We also present the results of a pilot user study. Some of our main observations are: When carrying out exploratory search tasks, classic search engines are mainly used as an entrance point to the web. Subsequently users work with several search systems in parallel, they have multiple browser tabs open and frequently use the clipboard to memorize, analyze and synthesize potentially useful data and information. Exploratory search tasks typically consist of various sessions and can span from hours up to weeks.

Ordinary search engine users assessing difficulty, effort, and outcome for simple and complex search tasks

Search engines are the preferred tools for finding information on the Web. They are advancing to be the common helpers to answer any of our search needs. We use them to carry out simple look-up tasks and also to work on rather time consuming and more complex search tasks. Yet, we do not know very much about the user performance while carrying out those tasks -- especially not for ordinary users. The aim of this study was to get more insight into whether Web users manage to assess difficulty, time effort, query effort, and task outcome of search tasks, and if their judging performance relates to task complexity. Our study was conducted with a systematically selected sample of 56 people with a wide demographic background. They carried out a set of 12 search tasks with commercial Web search engines in a laboratory environment. The results confirm that it is hard for normal Web users to judge the difficulty and effort to carry out complex search tasks. The judgments are more reliable for simple tasks than for complex ones. Task complexity is an indicator for judging performance.

The relationship between Internet user type and user performance when carrying out simple vs. complex search tasks

It is widely known that people become better at an activity if they perform this activity long and often. Yet, the question is whether being active in related areas like communicating online, writing blog articles or commenting on community forums have an impact on a person’s ability to perform Web searches, is still unanswered. Web searching has become a key task conducted online; in this paper we present our findings on whether the user type, which categorises a person’s online activities, has an impact on her or his search capabilities. We show (1) the characteristics of different user types when carrying out simple search tasks; (2) their characteristics when carrying out complex search tasks; and, (3) the significantly different user type characteristics between simple and complex search tasks. The results are based on an experiment with 56 ordinary Web users in a laboratory environment. The Search–Logger study framework was used to analyze and measure user behavior when carrying out a set of 12 predefined search tasks. Our findings include the fact that depending on task type (simple or complex) significant differences can be observed between users of different types.

Friend-to-Friend Computing - Instant Messaging Based Spontaneous Desktop Grid

Nowadays, grids are very heavyweight and complex. They need huge administrative capacities, just to keep the grid infrastructure running. If only a small job should be submitted, this administrative overhead is not justified. The initial metaphor for the computational grid being as easy as a power grid is still unfulfilled. To facilitate a public usage of Grids, we simplify grid computing using peer-to-peer computing and instant messaging. Instant messaging is used by the vast majority of computer users. We assume that using instant messaging techniques for the administrative part of setting up the grid will open grid capabilities to the public and thereby enable a desktop grid. We call the here applied paradigm friend-to-friend computing (F2F Computing). F2F computing offers the opportunity to spontaneously setup desktop grids with friends or colleagues via instant messaging. There is no server installation or maintenance needed. We describe the F2F computing framework, its implementation, future steps, and present the first results of running applications on top of it.

Impact of Gender and Age on performing Search Tasks Online

More and more people use the Internet to work on duties of their daily work routine. To find the right information online, Web search engines are the tools of their choice. Apart from finding facts, people use Web search engines to also execute rather complex and time consuming search tasks. So far search engines follow the one-for-all approach to serve its users and little is known about the impact of gender and age on peoples Web search behavior. In this article we present a study that examines (1) how female and male web users carry out simple and complex search tasks and what are the differences between the two user groups, and (2) how the age of the users impacts their search performance. The laboratory study was done with 56 ordinary people each carrying out 12 search tasks. Our findings confirm that age impacts behavior and search performance significantly, while gender influences were smaller than expected.

Service integration for biometric authentication

Multimodal biometric authentication systems offer immunity to the threats imposed by unimodal biometric systems. However, this comes at significantly higher development and adaptation costs. In this paper we introduce an approach that allows automatic configuration and deployment of heterogeneous biometric systems for different business processes and related environments. The need for development and integration of scenario-specific compatible systems is replaced by repetitive scenario-specific configuration and deployment of multimodal biometric systems. We also present tools for configuration and deployment, which respectively configure and deploy multimodal biometric systems comprising of heterogeneous open source and/or commercial biometric systems required for fulfillment of domain specific authentication needs. In comparison to the prevalent practices, our approach reduces the effort required for developing and deploying reliable biometric authentication systems.

DougFlow Offering Scientific Applications via Web Services

Scientific computation applications often consist of very different components that produce (or take as an input) huge amounts of data. Wrapping such components into web services to form a combined service for the scientific community has an additional complexity to deal with: how to organize data transfer within the web service framework efficiently enough to form high quality services that do not suffer in performance. In this paper we propose a method for processing large amounts of data transferred between different components of a compound web service. For this we develop a full workflow consisting of three separate components around an existing open-source package DOUG, a parallel black-box solver for large sparse systems of linear equations. We demonstrate the feasibility of the concept on an example of solving the steady state heat equations within design problems. The workflow involves a full production cycle, starting with the design of the geometry of the underlying problem domain with appropriate boundary conditions and other parameters, formation of the discretized system to be solved by DOUG and visualization of the heat distribution as a result.