Simple Search Task Research Articles

The impact of point symbol similarity on visual search on maps

ABSTRACT The study presented in this paper investigates the impact of the similarity level of cartographic point symbols on visual search performance. Specifically, we explore the application of an algorithm for quantitatively assessing symbols’ shape similarity, and apply the results of such automated analysis in a simple target search task on a map with distractors of varying similarity levels. Our primary hypothesis posits that the more similar the target symbol and distractors, the more challenging the visual search becomes in terms of search efficiency and eye metric performance. In a controlled laboratory experiment utilizing eye-tracking device, 33 participants were recruited, and 60 map stimuli were tested with each participant. The results confirmed the hypothesis assumptions. However, symbols based on a round shape were consistently the easiest to find at every similarity level. Eye movement analysis revealed differences in absolute pupil size between male and female participants, possibly associated with cognitive load, although without affecting search time performance. Interestingly, scan-path speed decreased with an increasing level of similarity between the target symbol and distractors. The practical implication of this study lies in the potential development of tools to assist map designers in selecting symbols with low similarity, thereby ensuring improved map readability.

Chimpanzees (Pan troglodytes) recognize that their guesses could be wrong and can pass a two-cup disjunctive syllogism task.

When chimpanzees search for hidden food, do they realize that their guesses may not be correct? We applied a post-decision wagering paradigm to a simple two-cup search task, varying whether we gave participants visual access to the baiting and then asking after they had chosen one of the cups whether they would prefer a smaller but certain reward instead of their original choice (experiment 1). Results showed that chimpanzees were more likely to accept the smaller reward in occluded than visible conditions. Experiment 2 found the same effect when we blocked visual access but manipulated the number of hiding locations for the food piece, showing that the effect is not owing to representation type. Experiments 3 and 4 showed that when given information about the contents of the unchosen cup, chimpanzees were able to flexibly update their choice behaviour accordingly. These results suggest that language is not a pre-requisite to solving the disjunctive syllogism and provides a valuable contribution to the debate on logical reasoning in non-human animals.

Errors in visual search: Are they stochastic or deterministic?

In any visual search task in the lab or in the world, observers will make errors. Those errors can be categorized as “deterministic”: If you miss this target in this display once, you will definitely miss it again. Alternatively, errors can be “stochastic”, occurring randomly with some probability from trial to trial. Researchers and practitioners have sought to reduce errors in visual search, but different types of errors might require different techniques for mitigation. To empirically categorize errors in a simple search task, our observers searched for the letter “T” among “L” distractors, with each display presented twice. When the letters were clearly visible (white letters on a gray background), the errors were almost completely stochastic (Exp 1). An error made on the first appearance of a display did not predict that an error would be made on the second appearance. When the visibility of the letters was manipulated (letters of different gray levels on a noisy background), the errors became a mix of stochastic and deterministic. Unsurprisingly, lower contrast targets produced more deterministic errors. (Exp 2). Using the stimuli of Exp 2, we tested whether errors could be reduced using cues that guided attention around the display but knew nothing about the content of that display (Exp3a, b). This had no effect, but cueing all item locations did succeed in reducing deterministic errors (Exp3c).

Transforming graph data visualisations from 2D displays into augmented reality 3D space: A quantitative study

Modern video-based head-mounted displays allow users to operate along Milgram’s entire reality-virtuality continuum. This opens up the field for novel cross-reality applications that distribute data analytics tasks along this continuum to combine benefits of established 2D information visualisation in the real environment with immersive analytics. In this publication, we explore this potential by transforming 2D graph data from a planar, large-scale display in the real environment into a spherical layout in augmented reality 3D space, letting it appear as if the graph is moving out of the display. We focus on design aspects of this transformation that potentially help users to form a joint mental model of both visualisations and to continue their tasks seamlessly in augmented reality. For this purpose, we implemented a framework of transformation parameters that can be categorised as follows: transformation methods, node transformation order (groupings) and different ways of visual interconnection. Variants in each of these areas were investigated in three quantitative user studies in which users had to solve a simple cluster search task. We confirmed that a visual transformation from 2D to 3D helps users to continue their tasks in augmented reality with less interruptions, and that node transformation order should be adjusted to data and task context. We further identified that users can perform tasks more efficiently when a user-controlled transformation is used, while a constant transformation with fixed duration can contribute to lower error rates.

Understanding in-context interaction: An investigation into on-the-go mobile search

Recent years have seen a profound change in how most users interact with search engines: the majority of search requests now come from mobile devices, which are used in a number of distracting contexts. This use of mobile devices in various situational contexts away from a desk presents a range of novel challenges for users and, consequently, possibilities for interface improvements. However, there is at present a lack of work that evaluates interaction in such contexts to understand what effects context and mobility have on behaviour and errors and, ultimately, users’ search performance.Through a controlled study, in which we simulate walking conditions on a treadmill and obstacle course, we use a combination of interaction logs and multiple video streams to capture interaction behaviour as participants (n = 24) complete simple search tasks. Using a bespoke tagging tool to analyse these recordings, we investigate how situational context and distractions impact user behaviour and performance, contrasting this with users in a baseline, seated condition. Our findings provide insights into the issues these common contexts cause, how users adapt and how such interfaces could be improved.

Post-decision search in repeated and variable environments

AbstractWhen faced with a decision, people collect information to help them decide. Though it may seem unnecessary, people often continue to search for information about alternatives after they have already chosen an option, even if this choice is irreversible (e.g., checking out other cars after just purchasing one). While previous post-decision search studies focused on “one-shot” decisions and highlighted its irrational aspects, here we explore the possible benefits of post-decision search in the long run. We use a simple search task in which participants repeatedly decide whether to select the current alternative or continue to search for a better alternative. In a preliminary study we find that participants indeed conduct post-decision search even in unique environments, where information about forgone options cannot be used in future choices. In the main studies exposure to post-decision information was manipulated directly in unique environments, and was found to lead to better performance. The source of the observed improvement was further investigated with an explicit strategy elicitation methodology. We find that following exposure to post-decision information, people collect more data before generating thresholds. Thus, although post-decision search in unique environments might appear redundant, our results suggest it can help decision makers to modify their strategy and improve their future choices.

Priming of Pop-out does not provide reliable measures of target activation and distractor inhibition in selective attention: Evidence from a large-scale online study

Lamy, Antebi, Aviani, and Carmel (2008) reported that in a simple search task where participants located an odd coloured circle, the inter-trial relations could be used to derive robust and independent measures of target activation and distractor inhibition. When a target feature repeated there was a benefit, and when the previous target feature became the distractor feature there was a cost. These two measures correlated and were taken to reflect a measure of target activation. When the distractor feature repeated there was a benefit and when the previous distractor feature became the current target feature there was a cost, these two measures correlated and were taken to reflect a measure of distractor inhibition. In the current study we examined the same colour search task online on a large group of 312 participants. The results revealed significant effects of target and distractor repetition and switching. However, the correlations reported by Lamy et al. (2008) were non-significant. Instead we found the correlations between the two measures of repetition and the two measures of switching.

Influence of social presence on eye movements in visual search tasks

This study employed an eye-tracking technique to investigate the influence of social presence on eye movements in visual search tasks. A total of 20 male subjects performed visual search tasks in a 2 (target presence: present vs. absent) × 2 (task complexity: complex vs. simple) × 2 (social presence: alone vs. a human audience) within-subject experiment. Results indicated that the presence of an audience could evoke a social facilitation effect on response time in visual search tasks. Compared with working alone, the participants made fewer and shorter fixations, larger saccades and shorter scan path in simple search tasks and more and longer fixations, smaller saccades and longer scan path in complex search tasks when working with an audience. The saccade velocity and pupil diameter in the audience-present condition were larger than those in the working-alone condition. No significant change in target fixation number was observed between two social presence conditions.Practitioner Summary: This study employed an eye-tracking technique to examine the influence of social presence on eye movements in visual search tasks. Results clarified the variation mechanism and characteristics of oculomotor scanning induced by social presence in visual search.

Sound effects: Multimodal input helps infants find displaced objects.

Before 9months, infants use sound to retrieve a stationary object hidden by darkness but not one hidden by occlusion, suggesting auditory input is more salient in the absence of visual input. This article addresses how audiovisual input affects 10-month-olds' search for displaced objects. In AB tasks, infants who previously retrieved an object at A subsequently fail to find it after it is displaced to B, especially following a delay between hiding and retrieval. Experiment 1 manipulated auditory input by keeping the hidden object audible versus silent, and visual input by presenting the delay in the light versus dark. Infants succeeded more at B with audible than silent objects and, unexpectedly, more after delays in the light than dark. Experiment 2 presented both the delay and search phases in darkness. The unexpected light-dark difference disappeared. Across experiments, the presence of auditory input helped infants find displaced objects, whereas the absence of visual input did not. Sound might help by strengthening object representation, reducing memory load, or focusing attention. This work provides new evidence on when bimodal input aids object processing, corroborates claims that audiovisual processing improves over the first year of life, and contributes to multisensory approaches to studying cognition. Statement of contribution What is already known on this subject Before 9months, infants use sound to retrieve a stationary object hidden by darkness but not one hidden by occlusion. This suggests they find auditory input more salient in the absence of visual input in simple search tasks. After 9months, infants' object processing appears more sensitive to multimodal (e.g., audiovisual) input. What does this study add? This study tested how audiovisual input affects 10-month-olds' search for an object displaced in an AB task. Sound helped infants find displaced objects in both the presence and absence of visual input. Object processing becomes more sensitive to bimodal input as multisensory functions develop across the first year.

Queries in authentic work tasks: the effects of task type and complexity

Purpose The purpose of this paper is to investigate information retrieval (IR) in the context of authentic work tasks (WTs), as compared to traditional experimental IR study designs. Design/methodology/approach The participants were 22 professionals working in municipal administration, university research and education, and commercial companies. The data comprise 286 WTs and 420 search tasks (STs). The data were collected in natural situations. It includes transaction logs, video recordings, interviews, observation, and daily questionnaires. Findings The analysis included the effects of WT type and complexity on the number of STs, queries, search keys and types of queries. The findings suggest that simple STs are enough to support most WTs. Complex WTs (vs more simple ones) and intellectual WTs (vs communication, support and editing WTs) include more STs than other WT categories. Research limitations/implications Further research should address the problems related to controllability of field studies and enhance the use of realistic WT situations in test-based studies, as well. Originality/value The study is an attempt to bring traditional IR studies and realistic research settings closer to each other. Using authentic WTs when studying IR is still rare. The representativeness of the WT/ST types used in interactive IR experiments should be carefully addressed: in the work flow, people seldom consciously recognise separate “STs”. This means that STs may mainly be an academic construct even to the point that studying IR without a decent context does violence to the further understanding of the phenomenon.

Toward FRP-Based Brain-Machine Interfaces-Single-Trial Classification of Fixation-Related Potentials.

The co-registration of eye tracking and electroencephalography provides a holistic measure of ongoing cognitive processes. Recently, fixation-related potentials have been introduced to quantify the neural activity in such bi-modal recordings. Fixation-related potentials are time-locked to fixation onsets, just like event-related potentials are locked to stimulus onsets. Compared to existing electroencephalography-based brain-machine interfaces that depend on visual stimuli, fixation-related potentials have the advantages that they can be used in free, unconstrained viewing conditions and can also be classified on a single-trial level. Thus, fixation-related potentials have the potential to allow for conceptually different brain-machine interfaces that directly interpret cortical activity related to the visual processing of specific objects. However, existing research has investigated fixation-related potentials only with very restricted and highly unnatural stimuli in simple search tasks while participant’s body movements were restricted. We present a study where we relieved many of these restrictions while retaining some control by using a gaze-contingent visual search task. In our study, participants had to find a target object out of 12 complex and everyday objects presented on a screen while the electrical activity of the brain and eye movements were recorded simultaneously. Our results show that our proposed method for the classification of fixation-related potentials can clearly discriminate between fixations on relevant, non-relevant and background areas. Furthermore, we show that our classification approach generalizes not only to different test sets from the same participant, but also across participants. These results promise to open novel avenues for exploiting fixation-related potentials in electroencephalography-based brain-machine interfaces and thus providing a novel means for intuitive human-machine interaction.

Constructing Complex Search Tasks with Coherent Subtask Search Goals

Nowadays, due to the explosive growth of web content and usage, users deal with their complex search tasks by web search engines. However, conventional search engines consider a search query corresponding only to a simple search task. In order to accomplish a complex search task, which consists of multiple subtask search goals, users usually have to issue a series of queries. For example, the complex search task “travel to Dubai” may involve several subtask search goals, including reserving hotel room, surveying Dubai landmarks, booking flights, and so forth. Therefore, a user can efficiently accomplish his or her complex search task if search engines can predict the complex search task with a variety of subtask search goals. In this work, we propose a complex search task model (CSTM) to deal with this problem. The CSTM first groups queries into complex search task clusters, and then generates subtask search goals from each complex search task cluster. To raise the performance of CSTM, we exploit four web resources including community question answering, query logs, search engine result pages, and clicked pages. Experimental results show that our CSTM is effective in identifying the comprehensive subtask search goals of a complex search task.

Is a search template an ordinary working memory? Comparing electrophysiological markers of working memory maintenance for visual search and recognition

Visual search requires the maintenance of a search template in visual working memory in order to guide attention towards the target. This raises the question whether a search template is essentially the same as a visual working memory representation used in tasks that do not require attentional guidance, or whether it is a qualitatively different representation. Two experiments tested this by comparing electrophysiological markers of visual working memory maintenance between simple recognition and search tasks. For both experiments, responses were less rapid and less accurate in search task than in simple recognition. Nevertheless, the contralateral delay activity (CDA), an index of quantity and quality of visual working memory representations, was equal across tasks. On the other hand, the late positive complex (LPC), which is sensitive to the effort invested in visual working memory maintenance, was greater for the search task than the recognition task. Additionally, when the same target cue was repeated across trials (Experiment 2), the amplitude of visual working memory markers (both CDA and LPC) decreased, demonstrating learning of the target at an equal rate for both tasks. Our results suggest that a search template is qualitatively the same as a representation used for simple recognition, but greater effort is invested in its maintenance.

Ordinary search engine users carrying out complex search tasks

Web search engines have become the dominant tools for finding information on the Internet. Owing to their popularity, users of all educational backgrounds and professions use them for a wide range of tasks, from simple look-up to rather complex information-seeking needs. This paper presents the results of a study that investigates the behavioural search characteristics of ordinary Web search engines users. The aim of the study was to investigate (1) what makes complex search tasks distinct from simple search tasks and whether it is possible to find simple measures for describing their complexity, and (2) whether successful searchers show different search behaviours than unsuccessful searchers and whether good searchers can be identified via simple measures. The study included 56 ordinary Web users who carried out a set of 12 search tasks using current commercial search engines. Their behaviour was logged with the Search-Logger tool. The results confirm that the behaviour in the case of complex search tasks has significantly different inherent characteristics than in the case of simple search tasks. This can be proven by using simple measures such as task time, number of queries, or number of browser tabs used. We also observed that it is difficult to distinguish successful from unsuccessful search behaviour simply by using these measures. The implications of our findings for search engine vendors are discussed. The results of this study with a sample of ordinary users are insofar unique as they are valid for a wider population while most studies in the field are usually done using convenience samples such as university students.

Assessing the influence of letter position in reading normal and transposed texts using a letter detection task.

During word recognition, some letters appear to play a more important role than others. Although some studies have suggested that the first and last letters of a word have a privileged status, there is no consensus with regards to the importance of the different letter positions when reading connected text. In the current experiments, we used a simple letter search task to examine the impact of letter position on word identification in connected text using a classic paper and pencil procedure (Experiment 1) and an eye movement monitoring procedure (Experiment 2). In Experiments 3 and 4, a condition with transposed letters was included. Our results show that the first letter of a word is detected more easily than the other letters, and transposing letters in a word revealed the importance of the final letter. It is concluded that both the initial and final letters play a special role in word identification during reading but that the underlying processes might differ.

How do we use the past to predict the future in oculomotor search?

A variety of findings suggest that when conducting visual search, we can exploit cues that are statistically related to a target’s location. But is this the result of heuristic mechanisms or an internal model that tracks the statistics of the environment? Here, connections are made between the two explanations, and four models are assessed to probe the mechanisms underlying prediction in search. Participants conducted a simple gaze-contingent search task with five conditions, each of which consists of different combinations of 1st and 2nd order statistics. People’s exploration behaviour adapted to the statistical rules governing target behaviour. Behaviour was most consistent with a model that represents transitions from one location to another, and that makes the underlying assumption that the world is dynamic. This assumption that the world is changeable could not be overridden despite task instruction and nearly 1h of exposure to unchanging statistics. This means that while people may be suboptimal in some experimental contexts, it may be because their internal mental model makes assumptions that are adaptive in a complex, changeable world.

The relationship between Internet user type and user performance when carrying out simple vs. complex search tasks

It is widely known that people become better at an activity if they perform this activity long and often. Yet, the question is whether being active in related areas like communicating online, writing blog articles or commenting on community forums have an impact on a person’s ability to perform Web searches, is still unanswered. Web searching has become a key task conducted online; in this paper we present our findings on whether the user type, which categorises a person’s online activities, has an impact on her or his search capabilities. We show (1) the characteristics of different user types when carrying out simple search tasks; (2) their characteristics when carrying out complex search tasks; and, (3) the significantly different user type characteristics between simple and complex search tasks. The results are based on an experiment with 56 ordinary Web users in a laboratory environment. The Search–Logger study framework was used to analyze and measure user behavior when carrying out a set of 12 predefined search tasks. Our findings include the fact that depending on task type (simple or complex) significant differences can be observed between users of different types.

Examining users’ preferences towards vertical graphical toolbars in simple search and point tasks

The main purpose of this study was to investigate the nature of preferences and their relation to the objective measures in simple direct manipulation tasks involving both the cognitive process as well as the visually guided pointing activities. The conducted experiment was concerned with the graphical structures resembling toolbars widely used in graphical interfaces. The influence of the graphical panel location, panel configuration as well as the target size on the user task efficiency and subjects’ preferences were examined. The participants were requested to express their attitudes towards the tested panels before and after the efficiency examination. This subjective evaluation was carried out within the framework of Analytic Hierarchy Process (AHP; Saaty, 1977, 1980). The subjective results that were obtained showed significant differences in the subjects’ preferences towards examined panels before and after completing the tasks. It seems that the users are able to comparatively quickly change their minds after gaining some experience with the investigated stimuli. Additionally, the applied cluster analysis revealed that the subjects were not homogenous in their opinions, and they formed groups having similar preference structures.

The impact of task complexity on people’s mental models of MedlinePlus

This study explored the impact of task complexity on people’s mental models of MedlinePlus, an information-rich web space providing consumer health information to the general public. Thirty-eight subjects were randomly assigned to two groups, performing either simple or complex search tasks. After the search session, subjects’ perceptions of MedlinePlus were elicited using a concept listing protocol where subjects listed concepts concerning MedlinePlus in the order each concept occurred to them. The analysis of the concepts suggested that task complexity impacted subjects’ mental models by influencing the objects in the system that they perceived and represented, the specificity of the representations, their evaluations of and emotions about the objects, and the heuristics that they developed for what works and what does not in the system. The pragmatic aspect of mental models was represented by subjects’ descriptions of the steps that they would follow to tackle a hypothetical task. The analysis showed that task complexity affected the strategies that subjects perceived themselves using to solve new tasks using the system.

The construction of mental models of information-rich web spaces

This study investigated the dynamic process of people constructing mental models of an information-rich web space during their interactions with the system and the impact of task complexity on model construction. In the study, subjects' mental models of MedlinePlus were measured at three time points: after subjects freely explored the system for 5 minutes, after the first search session, and after the second search session. During the first search session, the 39 subjects were randomly divided into two groups; one group completed 12 simple search tasks and the other group completed 3 complex search tasks. During the second search session, all subjects completed a set of 4 simple tasks and 2 complex tasks. Measures of the subjects' mental models included a concept listing protocol, a semi-structured interview, and a drawing task. The analysis revealed that subjects' mental models were a rich representation of the cognitive and emotional processes involved in their interaction with information systems. The mental models consisted of three dimensions (structure, evaluation and emotion, and (expected) behaviors); the structure and evaluation/emotion dimensions consisted of four components each: system, content, information organization, and interface. The construction of mental models was a process coordinated by people's internal cognitive structure and the external sources (the system, system feedback, and tasks) and a process distributed through time, in the sense that earlier mental models impacted later ones. Task complexity also impacted the construction of mental models by influencing what objects in the system were perceived and represented by the user, the specificity of the representations, and the user's feelings about the objects. Based on the study results, recommendations for employing mental models as a tool to assist designers in constructing user models, eliciting user requirements, and performing usability evaluations are put forward.