1 Introduction
Search engines have become an integral part of our daily lives. According to a 2023 report, an overwhelming 93% of all web traffic flows through search engines [
53]. They not only facilitate information dissemination but also exert a profound influence on our beliefs, shape ideas, and mold the behaviors and perceptions of users [
11]. For instance, a past study revealed that partisan bias in search engine rankings can substantially influence the voting preferences of individuals yet to make a decision [
21,
22]. Despite the power they hold, search engines have long operated as black boxes, providing little to no explanation about why specific search results are displayed to users and the order in which they appear. This lack of transparency has led users to develop folk theories or incorrect concepts about search engine functioning. For instance, a previous study revealed that searchers mistakenly believe web search engines accept payment for higher-ranking positions in search results, beyond advertisements [
79]. The lack of transparency has also been linked to limited engagement with search results [
60] and has been shown to contribute to users’ difficulty in finding desired information [
23,
34,
79]. Therefore, researchers and scholars have advocated for making search algorithms more accountable by being more transparent and interpretable. Studies have shown that by explaining how search works and communicating more information about search results, we can help users be more efficient and effective searchers [
28,
43,
60,
67] as well as raise user awareness of biases in search engine results [
59].
Despite the acknowledgment of the potential benefits of search explanations, there is limited work in this domain, often focusing on narrow aspects of search (such as query transformations), exploring how searchers perceive search engine decision-making, or testing the utility of specific types of search explanations. A notable gap exists in our understanding of what users think about search explanations—do users truly desire them, and if so, what specific needs and potential benefits are they seeking? This study aims to bridge the gap in understanding user perspectives on search explanations. By investigating when “non-technical” users (defined in Section
3.1.2) question search results, we identify situations where additional explanations or context could enhance their understanding. We explore what information search engines can provide to support informed decision-making and examine if and why users need search explanations for their various search needs. To navigate this inquiry effectively, we leverage the framework of search objectives identified by Rose et al. [
71]. This framework categorizes web searches into distinct goal-oriented categories, providing a structured approach to understanding and analyzing users’ information-seeking behaviors. The framework includes categories such as
directed-close searches, where users seek a single, unambiguous answer to a specific question,
advice searches, aimed at acquiring guidance, ideas, suggestions, or instructions, etc. Our objective is to discern whether and why users find search explanations valuable in these specific scenarios, examining how search explanations contribute to the fulfillment of diverse search goals.
In this study, we also assess the utility of current search engine explanation features. Popular web search engines like Google and Bing have traditionally offered brief text snippets with each search result, highlighting relevant keywords to indicate content alignment with queries. In response to the growing demand for transparency and accountability, modern search engines have recently introduced more sophisticated features designed to provide search explanations and additional context for search results. However, there is a limited understanding of users’ awareness and the perceived effectiveness of these additional features. Our research endeavors to bridge this gap by investigating users’ perceptions of their usefulness. Overall, this study is guided by three fundamental research questions:
RQ1: Under what circumstances do users question the curation of search results? What additional information could facilitate their evaluation of the results?
RQ2: For what search objectives do users find search result explanations helpful or unhelpful? In situations where explanations are deemed useful, what are the perceived benefits? What are the characteristics that users desire from search result explanations?
RQ3: How do users perceive the effectiveness of the existing search result explanations and search result context provided by Google and Bing search engines?
To answer these research questions, we conducted a two-phase study. The first phase was an online survey aimed at screening participants and introducing them to various types of search objectives. The second phase was semi-structured interviews with 12 “non-technical” users, aiming to understand users’ needs from search explanations. The study revealed that users tend to question search result curation when they encounter irrelevant results, inappropriate content (like ads or pornography), unknown sources, or have doubts about the selection of top-ranked results. Understanding the concept of explanations presented a challenge for certain participants, yet others found them useful in context-specific situations, especially for complex or high-stakes topics like medical searches and for searches where the objective is to find products or places they need to physically engage with. They prefer concise, actionable explanations that can aid in refining search queries and provide a better understanding of search result perspectives. In terms of their perception of existing search explanations, participants found Google’s explanation too broad and obvious but appreciated the ability to provide feedback on search results and valued Bing’s webpage preview feature. Our study reveals that users desire explanations not only to elucidate how search results are curated but also to gain additional insights about search results, all while maintaining agency over their search journey. Overall, our study delineates situations where search explanations are sought, outlines pivotal explanation attributes, and offers design recommendations for search engines.
5 RQ2 Results: User Perspectives On the Effectiveness of Search Result Explanations
To address the second research question, we introduced the concept of search explanations to participants. Additionally, we presented them with their survey responses and prompted them to elaborate on their answers by explaining why they believed explanations would be either helpful or not helpful in each objective. Table
1 presents the search objectives. We encouraged them to use the example search queries they provided for each search objective to contextualize their responses. It is important to note that some participants found the concept of explanations challenging to comprehend, even after being presented with examples. In fact, two participants struggled to grasp the concept of explanations entirely. In this section, we explore the search objectives in which participants perceived search results as useful and not useful.
5.1 Utility of explanations in various search objectives
As evident from Table
1, for all search objectives except the first, the majority of participants found search explanations helpful. While participants describe explanations serving different purposes in different objectives (Section
5.2), we found that the need for explanations is also highly context-dependent. Participants sought explanations for tasks that require “
deep engagement” or when “
they have the mental capacity and time” (P11) to delve into the search topic. In contrast, for day-to-day searches, participants never “
second-guessed the search results” (P4) and thus, did not feel the need for explanations. Participants highlighted the importance of more detailed explanations in high-stakes topics such as medical-related searches, indicating a desire to know if reputable sources were being presented. However, for opinion-based topics, participants considered explanations to be less significant, as their focus was on acquiring information that aided in making personal decisions. As participant P6 stated, “
For how to vote by mail, you want like a government site or something...if you wanted advice on stuff like blood pressure you would want to uh you would definitely want to know why you are getting shown a website... for how to bake a cake, I wouldn’t really care to know exactly how they decided to show me the best recipe”.
Furthermore, participants highlighted that for searches where the goal is to find real-world service or product, explanations become particularly valuable as participants anticipate interacting with these products or visiting specific places. As P3 expressed—“[Explanations] would be very helpful because I actually have to go to those places... I actually am gonna be physically somewhere or involved with this product... so explanations would be really helpful”.
Participants generally found explanations unnecessary when seeking a single, unambiguous answer. For such searches, search engines often provide featured snippets or answer boxes, which are information boxes displayed at the top of search engine results pages (SERPs) to directly answer user queries without the need to click on any search results. The simplicity of such queries led participants to believe that explanations would only clutter the website and divert users’ attention. P6 explains, “For search goal like that. like midterm election date, Prime Minister, stuff like that... where it’s just a clear answer, there’s no debate as to what the answer is.if an explanation was added, I feel like it would sort of clutter the website in a way and just kind of distract me instead”. Trust in the search engine’s ability to provide accurate results for such search scenarios was also highlighted, with one participant mentioning, “I’m not really super concerned about where that definition comes from, as long as it’s from a trusted source and correct...which I would imagine all the top search results for Google on that search term would be correct.” (P4).
5.2 Perceived benefits of search results explanations for various search objectives
In this section, we present the perceived benefits of search explanations identified through the interviews for various search objectives. Table
3 provides a summary.
5.2.1 Explanations increase trust in search results:
Participants believed that search explanations had the potential to bolster trust by offering insights into the credibility of search results across various search objectives. As one participant explained, “So having an explanation about like why was this so highly ranked... like okay, this is like a reputable source, so it’s maybe if it’s like a journal, it’s peer-reviewed or experts or well-known people in the field are cited here, those kinds of things would be much helpful” (P5). Such credibility signals allow participants to “differentiate between [results]. and determine which are more trustworthy than others” (P6). Participants also indicated explanations could increase trust by mentioning if the search result is “paid content or sponsorship and is there not necessarily because of relevance, but because of money” (P5).
“I would like to see why I’m getting certain searches and certain results back and if something’s kind of boosted to get its way up there because if I’m learning about a topic I don’t wanna have to read 10 different articles to make sure what I’m reading is correct, I wanna be able to click on something, read through it, have some sense of reliability and uh and kind of move on.” - P8
5.2.2 Explanations could serve as decision-making tools by assisting in the selection of search results:
Participants expressed that explanations could assist with the decision-making process about picking which sites to open and explore further.
“Explanations could be useful in the decision-making process and helpful in picking which sites to open and explore further, if they had those kinds of explanations, it could indicate that the items are pulled from major online marketers and listed in highest to lowest or lowest to highest cost, that kind of things could be useful. ” - P7
5.2.3 Explanations can help in guiding the search process and refining the queries:
Participants highlighted that explanations could assist in understanding their own thought processes and guide them toward more relevant search results. They mentioned that searches where the goal is either to get an answer to an open-ended question or learn everything about a topic could benefit from explanations that help users comprehend the different options and make informed decisions about their search direction.
“Yeah, I think that would be helpful because if your question is open-ended or can be pretty deep and go a bunch of different ways….The explanations can help you understand your own thought process a little bit more.can help you understand better from seeing those options, understand where and choose where you want to go from there versus like high level at the beginning When you’re first typing in your original search, you probably don’t know those broader or those more specific uh levels of that at that point in time, otherwise you would have searched for something a bit more specific, to begin with ” - P2
Participants also suggested the idea of using explanations to categorize or classify information to help users find specific details or narrow down their search for the aforementioned search objectives. Such categorization would also allow them to quickly identify redundant information and focus on acquiring new knowledge, thus saving time and making the search efficient.
“You’re asking the open-ended question coz you need as much information as possible...in such case, explanations should sort the searches by category.so you start with general and then you get down to specific category” - P7
“I could hover [over the explanations]... I might be like, okay, but I know X, Y, and Z already, so I’m gonna skip that... but now I’m looking here and this has a new piece of information, and I jump in... having an explanation would save time and also help you narrow down what you don’t know. ” - P5
Participants also believed that explanations could enable them to “refine [their] search terminology and search terms to obtain results that were more specific to their situation” (P9). P3 further elaborated that search engines could achieve this by suggesting the use of Boolean operators, for example, asking users to “add one word, subtract one word, or change something” (P3) in the search query.
5.2.4 Explanations help in understanding the perspectives or categories shown in the search results:
The interviews revealed that explanations could play a vital role in enhancing users’ understanding of the perspectives and viewpoints presented in the search results, especially for searches where the goal is either to get an answer to an open-ended question or learn everything about a topic. As P4 mentioned, “having an explanation might make me think more about it like, ’Oh, so this perspective is not being shown or this website is not being shown because maybe the search engines found it not being appropriate or not being uh something and a viewpoint is being hidden or suppressed.”
Moreover, explanations can lead users to discover new approaches and viewpoints when approaching a problem. P5 emphasizes this point, stating that “
having an explanation as to why certain search results pop up more than others might help me...figure out like this is maybe a new technique I didn’t know or a new perspective I had never thought about.” By providing insights into the rationale behind the prominence of specific results, explanations offer users the opportunity to broaden their horizons and consider alternative perspectives or techniques. P1 further stated that they would want explanations to tell them “
which side is the information coming from?” to enable them to assess potential biases or agendas in the information presented to them by the search result.
5.3 Desired characteristics of search result explanations
Table
4 provides a summary of the desired characteristics of search result explanations as expressed by the participants. Their perspectives highlighted the importance of concise explanations, actionable guidance, indicators of credibility and reputability, and the inclusion of viewpoints in the explanations. Participants recognized the “
overwhelming nature of internet searches [that] require sifting through [large amounts of] information” (P11), and expressed a strong desire for concise explanations that provide quick access to relevant information. As P7 expressed—“
To be really helpful, information [in the explanation] would need to be a very quick read”. Second, participants expressed the need for explanations to be actionable, i.e. they assist users with either selecting the search result or guiding the search process. Some participants expressed interest in having user experience features that allow them to change the order of search results based on specific criteria. For example, P7 suggested the inclusion of a button that enables users to adjust rankings based on their preferences. Participants also emphasized the presence of indicators of credibility and reputability of search results in the explanations. Furthermore, participants stressed the need for explanations to indicate the viewpoints of the search results. Understanding the perspective or stance of the source can help users assess the alignment of their own views and make more informed judgments about the information presented. As P1 mentioned, “
I would want to know who is teaching me this thing... make sure that their views aligned with mine”.
6 RQ3: Users’ Perception of Search Explanations and Search Context Provided by Search Engines
During the interviews, participants were shown the search result explanations and additional context provided by Google (Figures
2c and
2d) and Bing (Figure
2e) search engines. Table
5 lists the key features shown by Google and Bing alongside each search result. Bing provides additional context about webpage source, and webpage preview, and lists popular recommendations related to the search result. On the other hand, Google provides source information, search explanations, links to personalization and privacy settings, and an option to provide feedback about the search result. Interestingly, none of the participants were aware of the existence of these additional data accompanying the search results. The participants expressed diverse perspectives on these features, offering insights into their perception and usefulness. We discuss the emerging themes below.
6.0.1 Option to access additional information is valued:
All participants acknowledged the value of having the option to access additional information about the search result in both Bing and Google search engines. As P7 noted, “That gives a person the searcher the option of taking the extra time to learn the extra information... and that’s always a good thing to have”. Participants also appreciated the concise presentation of the information presented by search engines, as one participant mentioned, “I like that it’s concise and doesn’t show you everything you want to see.you have to click somewhere else, which I do like because it’s like it makes it less cluttered I guess” (P6).
6.0.2 Broad and obvious explanations are not deemed useful:
Many participants did not find the content of the search explanations, currently only provided by Google, particularly useful, deeming it to be either obvious or too broad. P5 provided an example stating that their getting a specific result due to their location in the USA is not very helpful—“I don’t think the result in the region would be particularly helpful, especially if it’s as broad as the United States”. P2 concurred, expressing, “I feel like a lot of this information doesn’t necessarily help me out with some of those qualities that we were talking about.like the trust, the credibility, the efficiency”.
6.0.3 Contestability is desired in search:
The majority of participants appreciated the functionality provided solely by Google to remove search results and offer feedback. They saw this feature as a means to contest and influence the search results, granting them a voice in determining the relevance and accuracy of the displayed information. Participants appreciated the agency and empowerment that came with being able to shape the search results according to their preferences and needs. One participant emphasized the significance of user input, expressing the necessity of having such a feature—“I feel like it’s something that’s necessary to have something like this because if they did not include like a send feedback option, it would feel sort of wrong in a way, it would feel more so that like Google is saying, we know what’s right, we know what’s best, and you know, you don’t have a say in that” (P6).
6.0.4 Privacy and personalization settings:
Participants found the privacy and personalization settings provided only by Google to be helpful. The majority of them were not aware that they could change their privacy settings to alter the way Google collects their personal information to personalize the search results for them. Participants suggested that instead of having the privacy settings within the search explanations pop up, “it should be easily accessible and visualizable on the search result page itself” (P3).
6.0.5 Website previews increase search efficiency:
All 12 participants highlighted the usefulness of the website preview feature offered only by Bing that provides an overview of the website’s content. Participants expressed a preference for this feature as it allowed them to get a “whole vibe of the website without visiting it directly” (P2) and “jump to the parts that are relevant to one’s specific search” (P5).
6.0.6 Significance of recommendations along with search results:
Bing offers additional search result recommendations alongside the primary search results. Participants found them helpful especially when exploring a topic or seeking specific pieces of information. One participant stated, “I think that’s really helpful when you’re doing something that you’re maybe trying to learn more about a topic and you don’t know where to start... you can kind of follow it down a rabbit hole to something more specific” (P5).
6.0.7 Source information enhances trust:
The majority of participants expressed their appreciation for the additional information about the source presented by both Bing and Google, underscoring its role in bolstering the perceived reliability of search results—“ I think linking me to Wikipedia can help me get like a broader understanding of the source with like a decent amount of trust in the results I’m seeing there.” (P9).
6.0.8 Need to improve discoverability of explanation features:
For both search engines, participants found it challenging to locate these features, expressing a desire for improved discoverability and accessibility. For example, one participant noted, “I like that it’s there, I wish it was a little bit more transparent so you didn’t have to click on a bubble and like three dots get to that thing” (P5). On similar lines, P11 added, “I mean it’s so deeply layered... I don’t know if I’d ever be able to find it”.
8 Limitations and Future Opportunities
While our work offers valuable insights, it is not without limitations. Our study had a limited sample size and focused on English-speaking “non-technical” individuals residing in the United States, with a majority being White/Caucasian. Consequently, our findings do not comprehensively capture user expectations and preferences across diverse regions, and ethnic backgrounds. Regional variations can significantly shape users’ expectations from search results and in turn search explanations by influencing the specific nuances, cultural context, and contextual relevance they seek from search results. Similarly, the racial background of users can also have an impact. Users from specific racial backgrounds may feel marginalized or dissatisfied if they consistently observe under-representation or stereotyping in search results. In our study, our primary focus was on gaining a broad understanding of the helpfulness of explanations in specific search scenarios, laying the groundwork for more detailed investigations into these influential factors in the future.
We did not account for personalization in our study. For instance, consider location-based personalization, where, when users search for ‘Italian restaurants’, the relevance and practicality of information becomes crucial. Users are more likely to find search results satisfactory when aligned with their local context, which might diminish the need for detailed explanations. While personalization can significantly influence users’ satisfaction with search results and, subsequently, their need for explanations, we acknowledge this as an area for future studies to explore in depth.
Another limitation of our study stems from our definition of “non-technical” users, which relied on self-reported technical competence and educational degree. However, we recognize that the term “non-technical” encompasses a wide spectrum of characteristics, extending beyond education degrees to include factors such as digital literacy levels, critical-thinking skills, and awareness of information disorders such as bias and misinformation. Unfortunately, we did not collect data on these nuanced aspects. As a result, our study might not fully represent the complexities inherent in the “non-technical” user group, limiting the ability to draw robust conclusions about the specific needs and expectations of users within this category. For instance, users with high critical-thinking skills and advanced digital literacy might have sought detailed explanations for all search objectives, desiring more granular insights into search engine processes within explanations. Additionally, our study focused exclusively on Google and Bing search engines, omitting others such as Yandex, YouTube, DuckDuckGo, etc. Future studies should aim to address these gaps for a more comprehensive understanding and generalizability across diverse populations, regions, and search engines.
Our study interviews were conducted in September 2022, before the widespread incorporation of Language Models (LLMs) in search engines. These LLMs have disrupted the search dynamics by providing single answers directly at the top of search results. However, our findings still hold value as they highlight the importance of providing explanations and citations to enhance user trust in search results. There is a future opportunity to explore the role of search explanations within the context of LLMs. Understanding how explanations can be effectively integrated with these models is a crucial area for further research. Additionally, our study’s goal is not to delve into the kind of explanations that would be most helpful in different scenarios and contexts. Future research can investigate the effectiveness of various explanation formats, such as visual or interactive formats, and explore different types of explanations, like counterfactual or contrastive explanations, to enhance user understanding and engagement with search results.