QWERTY: The Effects of Typing on Web Search Behavior Kevin Ong Kalervo Järvelin RMIT University University of Tampere [email protected] [email protected] Mark Sanderson Falk Scholer RMIT University RMIT University [email protected] [email protected] ABSTRACT amount of relevant information for an underlying information need Typing is a common form of query input for search engines and to be resolved. In IIR, the focus is on the interaction between a hu- other information retrieval systems; we therefore investigate the man and a search system. The interaction can take place over three relationship between typing behavior and search interactions. The modalities, such as search by using/viewing images, speaking [17] search process is interactive and typically requires entering one or or traditionally by typing into a search box. In this paper we focus more queries, and assessing both summaries from Search Engine Re- on typing. sult Pages and the underlying documents, to ultimately satisfy some Nowadays, searchers expect rapid responses from search en- information need. Under the Search Economic Theory (SET) model gines [15]. However, the amount of useful information gathered of interactive information retrieval, differences in query costs will during the search process is also dependent on how well searchers result in search behavior changes. We investigate how differences are able to translate their search inputs (such as typing), into useful in query inputs themselves may relate to Search Economic Theory information output [2]. IIR is a collaborative effort between the by conducting a lab-based experiment to observe how text entries searcher and the system to answer an information need. However, influence subsequent search interactions. Our results indicate that research efforts have mainly focused on the changes inhuman for faster typing speeds, more queries are entered in a session, while search behavior as a response to system response delays [4, 12], both query lengths and assessment times are lower. rather than on the effort exerted by both humans and systems as part of the search process. Maxwell and Azzopardi [12] observed CCS CONCEPTS that as total time on queries increases, then more time will be spent on assessing the returned Search Engine Result Pages (SERPs). • Information systems → Users and interactive retrieval; • Query cost is inevitably tied to searcher’s own input interactions Human-centered computing → Text input; on the search interface itself. KEYWORDS Typing behavior has received renewed research attention re- cently [6, 10, 11] but not within the IIR community. In this paper, Search Economic Theory, Text Input, Web Search Behavior we study the relationship between typing speed and search behav- ACM Reference Format: ior, and how an individual’s search and typing behavior may be Kevin Ong, Kalervo Järvelin, Mark Sanderson, and Falk Scholer. 2018. QW- used as a factor for explaining IIR behavior. ERTY: The Effects of Typing on Web Search Behavior. In Proceedings of Conference on Human Information Interaction & Retrieval, New Brunswick, NJ, USA, March 11–15, 2018 (CHIIR’18), 4 pages. 2 RESEARCH QUESTIONS https://doi.org/http://dx.doi.org/10.1145/3176349.3176872 The main research question studied in this work is: "What is the relationship between a user’s 1 INTRODUCTION typing speed and their search behavior?" Interactive Information Retrieval (IIR) researchers seek to under- stand the interactions between an information seeker and an in- The search process arises in order to satisfy some information needs, formation retrieval system [7]. Modeling IIR interactions is a non- and SET suggests that when query costs increase, more time will be trivial process as many factors can contribute to differences in the spent on assessments. We investigate if typing speed can be used as search behavior. The search process itself is an iterative sequence an indicator to understand the differences that might contribute to of actions that often requires multiple queries to acquire the desired different query-assessment trade-offs, by considering the following specific research questions. Permission to make digital or hard copies of all or part of this work for personal or RQ1, What is the relationship between typing speed and the classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation number of queries and assessment time per query? Azzopardi on the first page. Copyrights for components of this work owned by others than ACM et al. [2] postulated that user search interactions can be modeled by must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, an economic theory. We seek to understand how the cost of typing to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from [email protected]. can be incorporated into such a model. CHIIR’18, March 11–15, 2018, New Brunswick, NJ, USA RQ2, Will a faster searcher type more characters per query? © 2018 Association for Computing Machinery. As the effort to type is lower for faster searchers, we seek tounder- ACM ISBN ISBN 978-1-4503-4925-3/18/03...$15.00 https://doi.org/http://dx.doi.org/10.1145/3176349.3176872 stand if they will choose to issue queries that are longer. RQ3, Do differences in typing speed for different topics re- Searchers: 36 searchers (18 males and 18 females) aged from flect a user’s topic interest and familiarity? Past work found 18–47 with a mean age of 26 were recruited via opportunistic sam- that changes in searchers’ behavior can be measured from their pling at a local campus library. While 13 participants reported that emotion and typing behavior [5, 10]. Informed by Kelly and Cool [9], English was not their first language, all participants were confi- we seek to understand how topic interest and familiarity may be dent in reading and typing in English. A 15" Macbook laptop was associated with differences in the typing behaviors of searchers. provided for the experiment, and participants were asked if they were familiar with the type of keyboard; half reported that they 3 BACKGROUND were unfamiliar with the keyboard provided. The participants were told they had 45 minutes in total to complete six topics, and were Past work on SET and typing behavior revealed how different compensated at the end of the experiment with a $20 voucher for search costs may give rise to different search behaviors. Using the participation. Interaction-Cost hypothesis [1], we propose that query cost based Data: Data were collected as part of a larger experiment where on typing effort can be used as a factor to explain the trade-offs individual search interactions were collected [13]. Participants were between alternative search strategies in IIR. given two attempts at an initial typing test. The test allowed the SET proposed that differences in query costs will result in changes participants to familiarize themselves with the keyboard. They in search behavior [1]. The search process is a combination of inputs were then asked to conduct searches for six provided informa- (Q, A) per search session, where tional search tasks. Unknown to the participants, the initial SERPs • Q is the number queries that a user will issue, were controlled by varying quality of search results on the first • A is the number of assessments per query. page [13].1 Search results for any query reformulations per task A refers to both assessments of SERPs and web documents. The were obtained from a live commercial search engine. Participants combination of (Q, A) will be dependent on the relative cost of a were asked to carry out the tasks as they would on a normal web query against the cost of assessing a web page. The cost estimations search engine. Task order was rotated and counterbalanced with can either be interaction-based [2] or time-based [12]. Under the different types of initial starting conditions. They were able to enter interaction-based approach [2], the combination of (Q, A) produces as many queries as they liked, and were asked to find as many a cumulative gain (CG), which can be measured as relevant search results as they needed to satisfy the search task. д(Q, A) = α ∗ Qβ ∗ A(1−β ) Participants were free to distribute their time as they saw fit and where the parameter α represents how well a searcher can convert were not pressed to complete each task within a set time frame. their interactions into finding relevant documents, and β is the Total time remaining was provided to the participants if requested, relative cost of Q to A. but was otherwise not indicated. Maxwell and Azzopardi [12] studied the effect of query cost on Participants could mark a search result as relevant within the search behavior by subjecting users to two forms of delays: five SERP itself by clicking a checkbox, without having to open the seconds SERP response delays, or five seconds document download underlying document (which they could do, should they choose delays. They found that when total querying time increased, docu- to). Participants were also given both a pre-task questionnaire on ment assessments increased. Similarly, when both SERP response topic interest and familiarity, and post-task questionnaire on topic and document download delays were introduced, users spent more difficulty for each task. time examining documents. Logging: To capture typing behavior, a search engine interface Typing Salthouse [14] studied the effects of age and skills on was created to log the typing speed of each query using JavaScript. typing behavior, and found that experience but not age influenced The following interactions were logged: typing speed.