How do children find information on different types of tasks? Children's use of the Science Library Catalog - information retrieval system - includes appendix on search tasks - Children and the Digital Library

Library Trends, Spring, 1997 by Sandra G. Hirsh

3. Does the amount of prior knowledge children have about the topic influence information retrieval results on an automated library catalog?

The results found that domain knowledge influenced search success on all types of tasks. The task analyses found that children with high domain knowledge, regardless of the complexity of the task or the science/ technology topic, performed better on information retrieval tasks than children with low domain knowledge. These findings support prior research on the influence of domain knowledge on information retrieval with adult searchers (Allen, 1991; Hollands & Merikle, 1987; Hsieh-Yee, 1993; Marchionini et al., 1990, 1991, 1993) and the findings from the expert-novice literature in other fields (e.g., education and psychology), which found that children who are domain experts performed better on problem-solving and memory tasks than domain novices (Ceci, 1989; Chi et al., 1989; Gobbo & Chi, 1986). Children with high domain knowledge had well-defined and developed knowledge bases that enabled them to perform information retrieval tasks more successfully. Similar to Marchionini, Dwiggins, Katz, and Lin's (1993) findings regarding adult subject experts, children with high domain knowledge were better able to make relevance judgments and to evaluate whether the retrieved information actually answered the search questions. These findings on the effect of domain knowledge on children's information retrieval must be interpreted cautiously. Given that science grades were used to measure children's science domain knowledge, variations in search success and search behavior by level of domain knowledge may also be influenced by children's attitudes toward the subject of science and motivation for learning about science, elements not measured in the study.

4. Does success on search tasks vary by search options?

The search behavior data suggested that children's success rates varied on search tasks depending on the search methods employed. This discussion evaluates performance in terms of each of the search behaviors: keyword, browse, and mixed.

Children who used the keyword method exclusively were 100 percent successful on every task, but only six children fell into this category. The implementation of the keyword search method, with its spelling correction program, ranked output, relatively short results displays and additional subject context given by placing the keyword searches in the browsing hierarchy, appeared to allow these children to be highly successful in finding bibliographic information. Even with these enhancements, query formulation for search options requiring children to type in their search queries remains problematic. For example, some children typed in natural language queries, such as "how much sunlight and water does a plant need" to search for books on "growing garden crops." While this query successfully resulted in book records on the topic of growing garden crops, natural language queries may not be supported in other information retrieval systems.