The study examined age-related differences in behavioural and ocular strategies to search for information during web navigation within a website as a function of prior domain knowledge (high level vs low level) of users and search problem complexity (simple vs difficult problems). 23 older adults and 20 young adults had to answer ten search problems in two domain knowledge within two experimental websites (one for each domain): health and fantasy movies. In each domain, participants had to complete three simple problems (the main words of the instructions corresponded to links on the menu bar) and seven complex problems (the main words in the instructions were not present in the menu bar, so participants had to infer the relevant categories from the menu bar to find the information). Results showed that older and young adults adopt different strategies for searching for information through a specific website. Prior domain knowledge helped older adults improve navigation using more relevant navigational paths, improving time spent on relevant pages and reducing the number of areas visually explored on the website. By contrast, young adults adopted the same search strategies regardless of the task complexity and the level of prior knowledge domain required by the task.

This study explores the acceptability of a humanoid robot in the homes of deaf children with cochlear implants. Traditional audiologic rehabilitation, usually conducted at hospitals or clinics, significantly improves communication but geographical distance and parental availability pose challenges for families. Introducing home training with a humanoid robot could provide greater equity in care distribution, aid in the child’s progress, and offer an ecological approach. Here, ten families (11 cochlear-implanted (CI) children aged 7–12 years and their parents) participated in a study evaluating the acceptability of the humanoid robot (called Pepper) in their homes for one month. We identified two distinct clusters among the 11 CI children. The first cluster ("younger CI Children") demonstrated better and higher scores for acceptability, usability, usefulness, emotion, and fun, and used the robot more than children in the second cluster ("older CI children"). We found a decrease in both duration of use and number of applications launched by CI children each week when interacting with the robot. Parents showed similar results to their children, with parents of younger CI children demonstrating greater acceptance of the robot. Various technical issues (transcription errors, robot non-responsiveness, and comprehension difficulties) may have affected the robot’s acceptability among both CI children and their parents. Both CI children and parents expected humanoid robots to have more advanced capabilities, including high social intelligence, advanced artificial intelligence, voice assistant features, and Natural Language Processing integration.

While a clear distinction is established between simple lookup tasks and complex exploratory tasks, few studies have documented the differences between complex lookup tasks and simple exploratory tasks. To address this empirical gap, which has implications for system adaptability, the present study focused on these differences and the impact of users’ prior domain knowledge (low vs. high) on exploration-exploitation search strategies (thematic and navigational). The effects of prior domain knowledge on information search performance were also investigated, as well as the extent to which the navigational and thematic search strategies predicted users’ search scores and learning outcomes. Sixty students (35 in psychology, 25 in computer science) were asked to perform two complex lookup tasks and two simple exploratory tasks within and outside their knowledge domain. Results showed that when users performed tasks in their knowledge domain, they formulated more specific queries, achieved higher search scores, and produced higher quality factual knowledge. Complex lookup tasks led to more thematic exploitation and more navigational exploration than simple exploratory tasks. The search strategies predicted output performances differently, depending on the search domain (in vs. out). In light of these results, solutions helping users to improve their search strategies are given.

This study investigates how a search interface that displays users’ ultimate query (i.e. users’ current search goal) can cope with the age-related decrease of fluid abilities and support older users’ search behaviours. 30 young and 18 older adults completed 9 search problems with a regular web browser or with the experimental search interface. Results showed that older adults spent longer time on the search engine result pages, they needed more time to reformulate, and they had more difficulties exploring the search paths elaborated. Age-differences also appeared as soon as the beginning of the search. The support tool helped older users reformulate their queries more rapidly and elaborate more flexible search strategies at the beginning of the activity. Indeed, older adults who interacted with the support tool switched to the processing of a new search path more rapidly instead of exploiting their initial query (i.e. they visited fewer websites for the initial query produced and reformulated a query instead of keeping on conducting a deeper investigation of the search results provided in the search engine result page). Implications of these findings for the design of effective support tools for older users are discussed.

Handing-over objects to humans (or taking objects from them) is a key capability for a service robot. Humans are efficient and natural while performing this action and the purpose of the studies on this topic is to bring human-robot handovers to an acceptable, efficient and natural level. This paper deals with the cues that allow to make a handover look as natural as possible, and more precisely we focus on where the robot should look while performing it. In this context we propose a user study, involving 33 volunteers, who judged video sequences where they see either a human or a robot giving them an object. They were presented with different sequences where the agents (robot or human) have different gaze behaviours, and were asked to give their feeling about the sequence naturalness. In addition to this subjective measure, the volunteers were equipped with an eye tracker which enabled us to have more accurate objective measures.