Exploratory Search

Several experimental studies have been conducted, using various attributes in their definitions of exploratory search [163]. The usual general definition refers to the investigation and exploration of information spaces for the purpose of learning and making discoveries [128, 149, 165]. The attributes categorized in Table 2.1 serve as a high-level conceptualization clarifying our understanding of the diverse definitions of exploratory search.

2.1 Current Understanding of Information Search 15 The attributes of the task description are the characteristics associated with what motivated the exploration. Common attributes in this category are thegoal, search topic, and degree of uncertainty.

Goal: In exploratory tasks, the search goals are open-ended or general in nature, and they are poorly defined [51, 52, 96]. Here, the term “gen-eral” refers to conceptually broad goals with no specific target. They are commonly associated with learning or gaining new knowledge and/or in-vestigation [89, 107, 149, 157]. Often, explorers in an academic context are motivated to achieve a higher level of intellectual development within the search domain [149, 157]. Another common goal in exploration is compari-son among several topics/areas [96, 107]. An example expressing a compar-ison goal is that of a student who is considering a university for graduate studies, exploring and comparing all possible universities in a certain geo-graphical region [4]. For most tasks with this attribute, there is no specific answer that satisfies the information need; rather, there are many suitable results, which vary in their degree of relevance [53, 89, 109, 157]. For reason of these fairly loose constraints [136], users in this scenario target multiple documents [149].

Search topic: In many situations, topics for exploratory search arise through discussion/interaction with other people. For example, a professor may ask a student to learn about an emerging research area [11], or someone who has learned of a family member having been diagnosed with a disease may be interested in investigating that disease in more depth [169]. In both scenarios, another person has motivated the search. In exploratory search, the topics are general and multifaceted, which means that they cover many concepts [92] and most often involve a broader domain, with several sub-topics [53, 54, 128]. Many prior studies have examined exploratory search tasks that require finding information on an unfamiliar or at least less familiar topic [76, 118, 168].

Uncertainty level: When performing exploratory tasks, the information-seeker is uncertain about what queries to make, what results are relevant, and where to begin the search [107, 157]. Some researchers have referred to this phenomenon as the user facing difficultly in determining in advance which information is required for addressing the need [89]. Previous work shows that during the initial iterations of exploration, the user tries to make sense of the search domain to reduce the degree of uncertainty [53, 157].

The attributes of the search process are the characteristics of the in-formation search behavior while the user is engaged in search. Three at-tributes of the search process are considered here: duration, search path, and collaboration.

Duration: Exploration is considered a longitudinal process [157]. Ac-cording to the literature, it might involve multiple query iterations and multiple search sessions [128, 157], continued over a long span of time [54].

Search path: With exploratory tasks, we cannot identify a single and direct path that leads to the desired results [157]. As the user keeps explor-ing, knowledge and the information need continue to change [35, 54, 153].

There are also changes in the searcher’s motivation and interests [96, 97].

These dynamic factors render it impossible to predict at the outset what kind of queries the user might issue, what links will be followed, and when the user will terminate the search. The path in exploratory search indicates a browsing-based strategy; that is, the user navigates through broader areas of information rather than focusing on a single, narrow information patch.

Collaboration: Many exploratory searches are prompted by a discus-sion or other interaction with someone else, so it is unsurprising that the information-seeker might interact with several people in the course of the search process [115]. There could also be many people interested in the out-come / the findings. The following example is an exploratory task posed in a prior study that involved interaction with an external person:

Your great granny’s doctor has told her that getting more exercise will increase her fitness and help her avoid injuries. Your great granny does not use the Internet and has asked you to create an exercise program for her. She is 90-years old. Put together two thirty-minute low-impact exercise programs that she could alternate between during the week. [ [169], p. 4]

When performing this task, the searcher might interact with another per-son, who may have more knowledge of the topic. Exploration could involve collaborating in embarkation on the journey, during the exploration itself, and in the presentation or finalization stages of the search process [94].

User perception refers to how the user subjectively assesses his or her performance of the task. Subjective complexity is an important attribute of user perception [99]. In general, users perceive exploratory search tasks to be difficult. In some guidelines, perceived complexity is not considered a key attribute, however [96]. Some researchers have proposed that exploratory search tasks are perceived to be complex because of the lack of support provided by existing information retrieval systems [154], but, at the same time, there are several works that articulate exploratory search tasks as complex problems [118].

2.1 Current Understanding of Information Search 17

Table 2.1: Attributes of exploratory and lookup search tasks.

Attributes Exploratory search Lookup search Task description crite-rion, navigation to a known target, precise result set and where to find the information

Certainty about what kind of information to expect, carefully specified queries, precise results, minimal need to examine the results Search process imme-diately upon finding of the answer

Search path No predictable or struc-tured path, dynamic path,

Search mostly by the indi-vidual user