This study aims at investigating query formulation and reformulation patterns within the search procedure focusing mainly on the semantic aspect of submitted queries. Results identified generalisations, specifications, parallel movements and replacements with synonyms; the parallel movement came first in the users' preferences for reformulating a query. Additionally this study revealed that users used terms identified within the retrieved result sets for reformulating their queries. Users also used provided terms for formulating their queries while some terms that users typed in either for formulating or reformulating their queries were repeated even in queries with no strictly related subject of interest. Regarding the length of the queries outcomes showed that users, consistently to previous studies, typed in mostly one word per query. Furthermore, approximately half of the terms users chose for carrying out their searches were actually included in the Eurovoc thesaurus. ©2008 IEEE.