Abstract

1. INTRODUCTION
Two dominant ways of finding information on the Web are through the use of Web search engines and Web directories. As the Web became the major source of information for many users, the way
users search the Web became a crucial issue. Studies on the Web search appear regularly [1], reporting user search patterns and effectiveness of the search engines. This paper analyses how users search WWW.HR – the Croatian Web directory, and its effectiveness in providing relevant response to users' queries.

2. CASE STUDY
The WWW.HR is a Web-based information service supported by the Croatian Academic and
Research Network – CARNet. Established in 1994, WWW.HR tends to be a thematic portal, providing
regional information specifically concerning Croatia. WWW.HR consists of two services: general
facts about Croatia and a bilingual Web directory. The directory is a hierarchically organized, fully
searchable catalogue of Croatian or Croatia-related Web sites. Its top level contains 14 categories and an ever growing number of subcategories [3].

Sites are submitted by their authors. Upon the submission, the site index is created based on the
information provided by submitters:

• Site name in Croatian and English,
• Site description in Croatian and English,
• Site URL,
• Category names in Croatian and English,
• META keywords extracted from the page.

Based on user's input, the directory index database is queried and matching results returned to the
user, containing the list of submitted sites that match user's query. Several types of queries are
supported:

• All keywords (default query),
• Logical expression (using and, or, not, +, - and parenthesis),
• Queries with wildcards ('*' representing any keyword suffix),
• Phrase (any text in quotation marks).

3. ANALYSIS
In order to assess users' behaviour, the query statistics were generated from site access log during
the period of May 6th – June 16th, 2004. During that period, the directory received more than 2,000,000 pageviews in almost 450,000 sessions, with almost 10% of pageviews directed to search facility (session is a set of requests coming from the same IP address in the period of 15 minutes). From the data from the log file, the following was analysed:

• Number of terms per query,
• Use of advanced search features,
• Query spelling,
• Frequency of queries,
• Distribution of queries in time,
• Query results returned to the user.

The results show that the average length of the query is 1,54 terms, more than 60% of the queries
contain only one query term, while slightly more than 3% contain more than 4 query terms. Advanced
query features such as logical operators or stemming are very seldom used (1,28% of all valid
queries), but more than 7% of total query terms were misspelled (according to the Hascheck spelling
checker [4]) Also, the analysis showed that 20 most frequently used query terms are found in 12% of
queries. As to the results returned to the user, 30% of queries yielded no results at all, and 35% of
queries returned more than 15 results.

4. RESULTS
The results show that the average length of the query is 1,54 terms, more than 60% of the queries
contain only one query term, while slightly more than 3% contain more than 4 query terms. Advanced
query features such as logical operators or stemming are very seldom used (1,28% of all valid
queries), but more than 7% of total query terms were misspelled (according to the Hascheck spelling
checker [4]) Also, the analysis showed that 20 most frequently used query terms are found in 12% of
queries. As to the results returned to the user, 30% of queries yielded no results at all, and 35% of
queries returned more than 15 results.

5. CONCLUSION
In the study of users' search patterns, we analysed almost 300,000 user queries from to the biggest
Croatian Web directory. We found that most users use one or two query terms, make a fairly large
amount of spelling errors and seldom use advanced search features. Although the results show that
users' search patterns are in compliance with similar research on other search engines [1], [2], they
clearly indicate that users fail to recognize the difference between the search engine which crawls the
Internet and indexes the pages it encounters, and the web directory. They obviously expect to see the
same results from their queries. The high percentage of queries that return no matching results or too
many matching results indicates the need for new search mechanisms on the directory and thus
presents a challenge which is being addressed through the use of ontologies [5]. One of the ways to
define an ontology is by analysing which query terms return the same or similar results and combining such query terms into one ontology.

6. REFERENCES
[1] Amanda Spink, Dietmar Wolfram, B.J.Jansen, Tefko Saracevic: "Searching the Web: the public
and their queries", JASIS (Journal of the American Society for Information Science), 2000,
52(3):226-234
[2] Steen Christensen, Hans J. Skovgaard: "Web Site Usability Metrics: Search Behavior – Search
Trends", Mondosoft, URL: http://www.mondosoft.com/, June 2004.
[3] Maja Matijašević, Gordan Gledec: "Implications of Web resource composite for Web server
workload characteristics", Proceedings of NEW2AN 2004, Sankt Petersburg, Russia, February
2004, pp. 189-193.
[4] Hascheck – Croatian Academic Spelling Checker – http://hacheck.tel.fer.hr/, June 2004.
[5] Damir Jurić, Maja Matijašević, Gordan Gledec: "Using Ontologies To Improve Search On
WWW.HR Web Directory", to be presented at CUC 2004.

Biography

Gordan Gledec is a research assistant at the Department of Telecommunications, Faculty of Electrical Engineering and Computing, University of Zagreb. He received his B. Sc., M.Sc. and Ph.D. degrees at the Department of Telecommunications in 1996, 2000. and 2004, respectively. The title of his PhD thesis was "Metrics for Web Site Usability Evaluation". His main interests include Internet and Web technologies and UNIX administration. He has been an associate at the WWW.HR project since July 1997, and project leader since 2003.

Igor Ljubi received his B. Sc. and M.Sc. in Electrical Engineering from the Faculty of Electrical Engineering and Computing, University of Zagreb, in 1999. and 2003. respectively. He has been working at the Faculty of Electrical Engineering and Computing as an associate assistant since March 1999. His research interests include software engineering, mobile agents and WWW programming. He is involved in the CARNet project "WWW.HR – Homepage of the Republic of Croatia" since 1999. He is a member of the IEEE, and is actively involved in IEEE Student Branch Zagreb.