- Purpose – Query expansion and query limitation are two known techniques for assisting users to define efficient queries. The purpose of this article is to examine the effectiveness of the two methods. Design/methodology/approach – The research entailed an objective and subjective evaluation of the effectiveness of automatic and interactive query expansion and of two query limit options. The evaluation included both lab simulations and large-scale user studies. The objective aspects were evaluated in lab simulations with experts judging user performance. The subjective analysis was carried out by having the participants evaluate the quality of, and express their satisfaction with, the retrieval process and its results, thus employing perceived-value analysis. Findings – The main findings reveal a difference between the perceived and real values of these techniques. While users expressed their satisfaction with interactive query expansion and its performance, the real-value analysis of their performance did not show any significant difference between the retrieval modes. Originality/value – The article evaluates the objective and subjective effectiveness of automatic and interactive query expansion and two query limit options.