Query formulation is an essential part of successful information retrieval. The challenges in formulating effective queries are emphasized in web information search, because the web is used by a diverse population varying in their levels of expertise. In this paper, the factors affecting query formulation in web information search were studied. The data was collected via a questionnaire (32 participants, each formulated 20 queries). The results of the study suggested that experience in using computers, web, and web search engines affect the query formulation process. Surprisingly, domain expertise did not have an effect on the query formulation. Generally, experienced users formulated longer and more specific queries whereas the queries of users with less experience consisted of fewer and more generic terms. Based on the previous studies concerning query formulation and the results from the questionnaire study, three main factors