A conceptually relaxed utilization of the variable “search experience” makes it difficult for researchers to perform meaningful cross-study comparisons. The purpose of this study was to examine how search experience is defined and measured when used as a research variable. We implemented a qualitative analysis of 32 library and infor- mation science (LIS) research articles. We found that there was inconsistent terminology usage and measurements. Specifically, there were 21 unique labels to describe the search experience and 18 different measurements. The majority of the studies used a generic label “search expe- rience” and relied on the reader to grasp specific context of the electronic information retrieval environment to which the variable applies from the description of the overall research design. In addition, there was a strong preference for measures that represented subjective self- reporting about the level of exposure to some information retrieval system. It is evident that there is a need for arti- cles to contain detailed definitions of search experience variables for readers to truly understand the findings. Introduction The information users’ facility with electronic information retrieval (IR) systems has been widely recognized as an important element in the research on information systems usage. While many researchers have accounted for search experience in their research designs, there appears to be lit- tle consistency in the operational definitions and measure- ments. In their comprehensive categorization of research variables applied in user studies and IR research, Meadow, Marchionini, and Cherry (1994), and Yuan and Meadow (1999) reinforced the importance of the consistent use of variables as a prerequisite for better communication among the researchers in the field. A conceptually relaxed utilization of the variable “search experience” makes it difficult for researchers to perform meaningful cross-study comparisons, prevents researchers from building on the outcomes from the previous studies, and ultimately contributes to conflicting findings about the impact of a user’s search experience on the processes and outcomes of IR systems use. As an initial step to facilitate future use of search experi- ence as a research variable, we conducted a comparative review of how this variable has been measured in a sample of 32 studies published in the key library and information sci- ence (LIS) research publications. In this article, we use the concept “search experience” as a label that broadly refers to any skill an individual possesses for using some electronic IR system. This concept consists of two key elements: • “Search” refers to techniques one applies when using an electronic IR system to find records of interest. • “Experience” means the accumulation of knowledge and skills needed to use an electronic IR system. We do not imply that “search experience” is the best possible label, but one that is broad enough to communicate effec- tively for the purposes of this article. Background The rapid developments of IR technologies have provided people with abundant opportunities to search for informa- tion with a variety of IR tools, and therefore have led to the development of various types of personal experiences with IR systems. Before the mid-1990s, researchers had focused on the users’ experiences with command-driven online biblio- graphic databases (e.g., ERIC, MEDLINE, Dialog) and online public-access catalogs (e.g., Fenichel, 1979; Hsieh-Yee, 1993; Marchionini, Dwiggins, Katz, & Lin, 1993; Penniman, 1981). This period also includes studies of some early, stand- alone hypertext systems (e.g., Marchionini, Lin, & Dwiggins, 1990). With proliferation of the Internet and the Web, the Web search engines gained popularity among the users, which in turn ignited research interest in users’ experiences with the Web-based IR systems (Lazonder, Biemans, & Woperis, 2000; Navarro-Prieto, Scaife, & Rogers, 1999; Palmquist & Kim, 2000). A review of research studies that focused on the impact of user experience on IR systems usage reveals that there have been many mixed findings. For example, early work by JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, 58(10):1529–1546, 2007 The Search Experience Variable in Information Behavior Research Joi L. Moore, Sanda Erdelez, and Wu He School of Information Science and Learning Technologies, University of Missouri-Columbia, 303 Townsend Hall, Columbia, MO 65211. E-mail: moorejoi@missouri.edu Received August 15, 2005; revised July 24, 2006; accepted December 5, 2006 © 2007 Wiley Periodicals, Inc. • Published online 18 June 2007 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/asi.20635