The focus of the thesis is an information search technique called manual query expansion, which aims to improve the retrieval per-formance in a search system by adding terms to the search query. The study looks at the query expansions done by LIS students, and the eventual beneficial effects by using a search help during the search process. The empirical data have been collected thro-ugh an experiment, with an experiment group as well as a control group. The conclusion is that the students need more education in query expansion in order to be able to use it correctly. There are significant differences between the groups in several aspects, for example in the use of search terms, parentheses, and truncation. The study should be seen as a pilot study and a proposal for further research. / Program: Bibliotekarie