User Interactions with Internet of Things (IoT) Devices in Shared Domestic Spaces

This doctoral research aims to understand the dynamics and challenges faced by ’secondary users’ within shared smart home environments—individuals who interact with smart home technology in their homes but do not initiate or maintain it. It delves into potential power imbalances within shared smart homes, which may reinforce traditional gender roles and lead to conflicts. The research examines how roles are distributed within partnerships and families, focusing on involving secondary users in the design process for designing more inclusive smart home environments. The work is based on a series of interconnected studies, such as co-design workshops and expert interviews with book designers, to inform the design process of tangible user interfaces that can provide control, facilitate effective communication with other household members, and empower secondary users to actively shape their shared smart home environments.


INTRODUCTION
Typically, one person initiates the setup of shared residential Internet of Things (IoT) technology, often as a hobby [12], leading to disruptions in the routines of other cohabitants.Less-involved individuals are often hesitant to engage with Smart Home Technology (SHT) [10].As IoT networks expand with more features and connected devices, control and power distribution within households become uneven, reinforcing traditional gender roles [7,11] and potentially increasing the risk of technologically enhanced domestic conflicts.
My doctoral research focuses on understanding the experiences of 'secondary users' in smart homes -those who do not install or maintain devices but interact with them in their living spaces.The aim is to uncover cohabitation dynamics, identify potential tensions and conflicts, and develop recommendations and guidelines for user interfaces and features in shared smart homes, fostering a sense of control and autonomy for all cohabitants.

RELATED WORK
In Wózniak et al. 's study [12], contextual inquiries were conducted with 20 participants in their smart home.The study yielded insights into motivations for adopting SHT, perceived benefits, interconnectivity of devices, and trust and control perceptions regarding those.Additionally, the research highlighted diverse user roles, conflicts, and privacy concerns among cohabitants, particularly in multi-generational or non-family households [12].
Geeng and Roesner [4] conducted interviews and experience sampling with primarily smart home administrators in shared households.They identified four stages of significant multi-user interactions: (1) device selection and installation, (2) regular device usage, (3) troubleshooting, and (4) long-term use.Insights revealed that restricted access to device functionalities and knowledge gaps in setup often led to conflicts.
Rode and Poole [7] introduced the Socio-Technical Gender Model based on two studies on labor divisions and help-seeking practices in domestic technology, especially those involving networking and privacy/security strategies.They applied feminist theory to examine the co-creation of gender and technical identity, ultimately detailing users' roles and responsibilities concerning domestic technology through the lens of masculinity and femininity.
In my work, I move beyond investigating a smart home household as a unit, digging deeper in understanding the reason for role distributions, especially in partnerships and family settings, with a feminist lens [7].Other studies involved mostly those users that initiate and maintain the smart home technology in their research [4,12].
Different to previous work about cohabitation in smart homes [4,7,12], I follow a co-design approach to develop future directions of smart homes.By putting individuals who live in a smart home that they did not initiate into the role of co-designers for future features and devices, I aim to enhance secondary users' agency in shaping SHT to align with their preferences and needs.An objective is to challenge the consolidation of the distributed roles in shared households and encourage users in communicating and collaborating more effectively to the joined effort to appropriate their smart home ecosystems.

STATE OF THE WORK 3.1 Study 1: Material and Aesthetic Aspects for
Blended Smart Home User Interfaces Cultural probes followed by a co-design workshop series with 12 prospective secondary smart home users explored ideas for user interfaces that blend in with domestic spaces from a material and aesthetic perspective.The cultural probes served as preparation for the workshop (details published as short paper at MuC'22 [9]).The participants shared visions for smart surfaces that appear analog (e.g.e-textiles as described by Beruscha et al. [1]), based on which we assessed user expectations regarding the usability of hidden interactivity and general requirements for IoT technology to blend in with domestic spaces.Through thematic analysis [2], we developed two themes, which extend across five topics: that a smart home needs to "feel like home" and at the same time "contribute actively to the household" (published at MUM'22 [8]).A short summary of insights was sent retrospectively to the workshop participants, who were asked to provide comments and fill out the short AttrakDiff questionnaire [5], to make sure the interpretations aligned with their perspectives.

Study 2: Experience by Cohabitation
Another study investigated the dynamics between household members of state of the art smart homes, that are set up and maintained as a hobby.As a pre-study, we conducted an exploratory analysis of online forum threads, where smart home initiators discuss thoughts and experiences concerning their partner's acceptance and approval.
Insights from this served as topics for semi-structured interviews with 12 individuals, who are secondary users of SHT, as their partner, as a primary user, set up their shared smart home.We discussed the participants' user journey with their smart home, especially in initial stages, focusing on troubleshooting in case of malfunctioning and decision-making concerning the residential IoT devices and functionalities.
Then, transcriptions were analyzed with Reflexive Thematic Analysis (RTA) [2] and 3 themes were created: "creating a suitable smart home is an individual and joined process for each house", "smart home needs to be experienced first-hand to be appreciated", and "smart home is unevenly beneficial to household members".For each theme, design recommendations were formulated (published at Interact'23 [10]).
In addition, insights from this project were visualized as user journeys, that categorize two typical behaviors: one where the person gets involved with the SHT, one where the person does not engage and holds back their thoughts and ideas, similar to the classification as 'assisters' and 'consumers' described by Poole et al. [6].

Study 3 (ongoing): Knowledge and Communication in Shared Smart Homes
Independently, we are currently investigating what information smart home residents consider as relevant in their everyday life to gain an overview of the installed SHTs.Therefore, we conducted a cultural probe study [3] with ten tasks to be done by least 2 members of a shared smart home (having a minimum number of residential IoT devices for at least 6 months).The tasks varied between individual and collaborative assignments and involved reflections of their behavior, point of views, and future visions, descriptive tasks regarding the technological set ups, and a collaborative exercise where they are asked to integrate a smart light bulb (provided and serving as compensation for participation).35 participants from 16 households returned the probes so far.Based on the insights, a concept for a tangible interface was developed.The 'Tangible Documentation' resembles an analog folder that contains a list and classification of the available smart home components in the shared household and allows fundamental user interactions.Additionally, we are conducting semi-structured follow-up interviews with a subset of households in a video call, predominantly in a group setting with all cultural probe participants of a household that agreed to take part.The conversations cover how the participants are currently keeping an overview of installed SHTs, how household members communicate concerning the devices, how they collaborate to shape the SHT set up, and how they reflect on and revise the functionalities.Then, the smart home initiators are asked to leave, and the less-involved smart home users are interviewed separately.These are asked to elaborate their perspective on living with SHT, if they would live in a smart home if they would move to their own house or flat and how they would proceed with set up and maintenance.
The analysis of the returned cultural probes, follow-up interviews, and the evaluation of the 'Tangible Documentation' are currently in progress.

Study 4 (ongoing): Symbolic Values and Affordances of Books in Domestic Spaces
Based on the insights of the co-creation sessions for future smart home user interfaces in the first study [8], we identified physical books as objects in domestic spaces that hold many desirable characteristics in terms of aesthetics, tangibility and values.To justify the intuition to use physical books as inspiration, we conducted seven expert interviews with professionals with diverse backgrounds in book design.Participants' experience ranged from commercial and academic perspectives covering book design for publishers, being CEOs of publishing houses, owning an independent book store, professional manual bookbinding, restoring books, and researching books and fake books from various angles.The next step is now to synthesize the insights from the Thematic Analysis [2] concerning books' symbolic values and affordances that are desirable for tangible interfaces and create a material for researchers for designing user interfaces in shared residential environments (e.g., a toolkit or a card set for participatory design).The research material will be used and evaluated in a co-creation session with smart home users.To evaluate the research material created using the result of the book study (see section 3.4), we plan a co-design study.With the help of the toolkit or card set, we plan to iterate on the 'Tangible Documentation' (see section 2.3) to provide a better overview of and fundamental interactions with devices to secondary users.The focus will be on envisioning features for the user interface to support reflection and revision of the SHT in the shared households collaboratively.The creation of the material as well as the study design for the co-design study are currently in progress.We hope to conclude the project this year and submit its results to DIS'24.Before handing in my dissertation at the media faculty of the Bauhaus-Universität Weimar, I should have two published and a third submitted first-authored full papers at selected HCI conferences.I already published two first-authored full papers [8,10], a short paper [9], and co-authored a related publication [1].Two more first-authored full papers are currently in progress.I am allowed to write either a monograph or cumulative dissertation (which needs the publications).

FINALLY, INFORMATION ABOUT MYSELF
From the doctoral consortium, I hope for feedback on my projects and exchange on how to present the insights in the dissertation.I am looking for support in sorting my thoughts concerning the individual components, so that the red thread of my work becomes more visible and comprehensible.Further, I seek advice how I can sharpen and foster my contribution to the HCI community.As I am taking a feminist perspective in my doctoral research, I am curious to engage in discussions on how HCI can have an impact on the pursuit of gender equity, specifically in context of domestic technology and personal informatics.Generally, I hope for advice on the finalization of the dissertation and preparation of the defense.Furthermore, I am allowed to suggest an external reviewer for my thesis, and would welcome ideas and suggestions for this.

3. 5
Study 5 (planned): Reflection and Revision of Shared Smart Homes (Evaluation and Next Iteration of the 'Tangible Documentation')

I
'm a PhD Student at Robert Bosch GmbH since the 15th November 2020 working full time on my doctoral research, funded until end of 2024.My supervisors are Prof.Dr.-Ing.Eva Hornecker (Bauhaus-Universität Weimar) , Prof. Dr. phil.Oliver Korn (Offenburg University of Applied Sciences) , and Dr.-Ing.Frank Beruscha (Bosch Research).