The Efficacy of Google's suggested keywords and phrases in Query Expansion on postgraduate's View about retrieval relevance

The goal of information systems is to retrieve relevant information fulfilling users’ needs. According to this, search engines have offered a new capability as “suggested keywords”. This is an essential problem that how much these suggested keywords have compatibility with users’ needs. The present research aims to investigate the efficacy of Google's suggested keywords in query expansion and retrieval relevance from users’ view. Through a survey method data were collected from 60 postgraduate students in Humanities/ social sciences and Basic/ Engineering Sciences at Ferdowsi University of Mashhad, Iran. These data were collected by using a researcher-made questionnaire. Non-probability sampling –especially purposive sampling- was used as the sampling method. Also, individual interviews were established with each of the 60 students. Findings show that there is a significant difference between the relevance of retrieved results related to primary keyword search and results retrieved through query expansion (suggested keywords). Also there is no significant difference between retrieved results in the two fields of sciences. Finally, the paper suggests some solutions to improve retrieved results related to suggested keywords.