Tatiana Gossen

Specifics of information retrieval for young users: A survey

In this paper, we present the state of the art in the field of information retrieval that is relevant for understanding how to design information retrieval systems for children. We describe basic theories of human development to explain the specifics of young users, i.e., their cognitive skills, fine motor skills, knowledge, memory and emotional states in so far as they differ from those of adults. We derive the implications these differences have on the design of information retrieval systems for children. Furthermore, we summarize the main findings about childrens search behavior from multiple user studies. These findings are important to understand childrens information needs, their search strategies and usage of information retrieval systems. We also identify several weaknesses of previous user studies about childrens information-seeking behavior. Guided by the findings of these user studies, we describe challenges for the design of information retrieval systems for young users. We give an overview of algorithms and user interface concepts. We also describe existing information retrieval systems for children, in specific web search engines and digital libraries. We conclude with a discussion of open issues and directions for further research. The survey provided in this paper is important both for designers of information retrieval systems for young users as well as for researchers who start working in this field.

What are the real differences of children's and adults' web search

We present first results of a logfile analysis on web search engines for children. The aim of this research is to analyse fundamental facts about how childrens web search behaviour differs from that of adults. We show differences to previous results, which are often based on small lab experiments. Our large-scale analysis suggests that children search queries are more information-oriented and shorter on average. Children indeed make a lot of spelling errors and often repeat searches and revisit web pages.

Knowledge journey: a web search interface for young users

This paper describes a new user interface for a web search engine whose main target group are young users. We explain the main challenges for this user interface and discuss design decisions we made. Our interface is audio supported, contains possibilities for both searching through text input and navigating using menu categories, has a guidance figure for emotional support and a result storage functionality to support cognitive recall. It is also colourful which is appreciated by most children. A comparative study with 28 young users was conducted where we compared our user interface with a classic text search user interface provided by most current web search engines. We evaluated what features of both interfaces children like or dislike to further improve the interface.

Find it if you can: usability case study of search engines for young users

The Internet is an integral part of the lives of our children nowadays. Using the Internet, in particular search engines, children search for information for school, for their individual interests or simply for entertainment. Unfortunately, research shows that children face many difficulties when searching and browsing for information, even though there are several search engines that are designed especially for children. In this paper, we review recent work in this field and evaluate to what extent current search engines for children are appropriately supporting the motor and cognitive skills of elementary school-age children. We base our study on findings of previous research and derive criteria to assess existing search engines. Our results suggest that most of them still require improvements in order to fit the skills and competencies of children.

Data exploration for bisociative knowledge discovery: a brief overview of tools and evaluation methods

In this chapter we explain the definition of the term (data) exploration. We refine this definition in the context of browsing, navigating and searching. We provide a definition of bisociative exploration and derive requirements on user interfaces, which are designed to support bisociative knowledge discovery. We discuss how to support subtasks of bisociative data exploration with appropriate user interface elements. We also present a set of exploratory tools, which are currently available or in development. Finally, we discuss the problem of usability evaluation in the context of exploratory search. Two main issues - complexity and comparability - are explained and possible solutions proposed.

Graph clusterings with overlaps: Adapted quality indices and a generation model

Many real-world networks have a structure of overlapping cohesive groups. In order to uncover this structure several clustering algorithms have been developed. In this paper, we focus on the evaluation of these algorithms. Quality measures are commonly used for this purpose and provide a means to assess the quality of a derived cluster structure. Currently, there are too few measures for graph clusterings with overlaps available that would enable a meaningful evaluation, even though many well studied crisp quality measures exist. In order to expand the pool of overlapping measures we propose three methods to adapt existing crisp quality measures so that they can handle graph overlaps appropriately. We demonstrate our methods on the well known measures Density, Modularity and Conductance. We also propose an enhancement of an existing modularity measure for networks with overlapping structure. We analyse the proposed quality indices using experiments on artificial graphs that possess overlapping structure. For this evaluation, we apply a graph generation model to create clustered graphs with overlaps that are similar to real-world networks, i.e., their node degree and cluster size distribution follow a power law.

Targeted Search Engines for Children: Search User Interfaces and Information-Seeking Behaviour

Children are a fast growing user group on the Internet. Among different online activities, children use web search engines in order to gather information related to their personal interests and school activities. Childrens knowledge, cognitive abilities and fine motor skills are different from those of adults. Therefore, they may experience difficulties with search engines that are built using standard information retrieval algorithms and search interfaces for adults. Special or targeted search engines for children are essential in order to better support children in their search tasks. Therefore, the goal of this thesis is to design appropriate search engines for children with a focus on the search user interface. However, this is not an easy task to accomplish. Not only are childrens abilities different from the abilities of adults, children also undergo relatively fast changes in their abilities. The specific and dynamically changing characteristics of young users pose a great challenge. In order to address this challenge, first, the specifics of information retrieval for young users are analysed. Second, open issues are identified in user studies with children using logfile analysis and eye-tracking. The conceptual challenges in the design of user interfaces regarding search engines for children are derived based on the findings of ones own and previous user studies as well as theories of human development. Third, user interfaces of search engines that address these conceptual challenges are designed, prototypically implemented and evaluated in user studies with children following a user-centered design. Specifically, the proposed user interfaces of the search engine address the changing characteristics of the users by providing a means of adaptation. Furthermore, a novel type of search result visualisation for children with cartoon style characters is developed which takes the childrens preference for visual information into account. Both approaches were very positively received by children during evaluation. Children rated different user interface aspects of the search user interface prototypes as good, e.g., the adaptation of the search user interface towards user wishes and the helpfulness of the cartoon style characters during search. Finally, this thesis provides criteria and guidelines on how to design user interfaces of search engines for children.

Knowledge Journey Exhibit: Towards Age-Adaptive Search User Interfaces

We describe an information terminal that supports interactive search with an age-adaptable search user interface whose main focus group are young users. The terminal enables a flexible adaptation of the search user interface to address changing requirements of users at different age groups. The interface is operated using touch interactions as they are considered to be more natural for children than using a mouse. Users search within a safe environment; For this purpose a search index was created using a focused crawler.

On the integration of graph exploration and data analysis: the creative exploration toolkit

To enable discovery in large, heterogenious information networks a tool is needed that allows exploration in changing graph structures and integrates advanced graph mining methods in an interactive visualization framework. We present the Creative Exploration Toolkit (CET), which consists of a state-of-the-art user interface for graph visualization designed towards explorative tasks and support tools for integration and communication with external data sources and mining tools, especially the data-mining platform KNIME. All parts of the interface can be customized to fit the requirements of special tasks, including the use of node type dependent icons, highlighting of nodes and clusters. Through an evaluation we have shown the applicability of CET for structure-based analysis tasks.

My First Search User Interface

This paper describes an adaptable search user interface whose main focus group are young users. In order to address continuous and --- compared to middle-age users --- relatively fast changes in cognitive, fine motor skills and other abilities of young users, we developed a first prototype of an evolving search user interface ESUI. This ESUI is able to handle changes in design requirements. It is adaptable towards individual user characteristics allowing a flexible modification of the SUI in terms of UI element properties like font size, but also UI element types and their properties. In this work, the goal of SUI adaptation is emotional support for children because positive attitudes towards the system keep them motivated.