Conference Agenda

Assumptions are presented here as limits within which thinking operates. We ask how such limits emerge when people solve ill-structured questions which are akin to design problems. In a pilot study, 22 university students attempted short and long timed versions of such tasks and were subsequently probed about their initial thoughts. We analysed the responses using reflexive thematic analysis, considering the inability to verbalise how a thought comes to mind, imagery reports, and epistemic justification as behavioural traces of limit formation. Five themes were constructed: “Inside the Invisible Limit”, “From My Memory to Meaning”, “Projection While Solving an Ill-Structured Problem”, “Semantic Attributes of Stimuli vs. the Socially Shared Meaning”, and “My Knowledge is Valid: Epistemic Justification”. We propose a model of assumption-making in which an assumption is an emergent limit shaped by factors informed by these themes. These findings offer early building blocks for a theory of assumption-making.

In this paper, we explore alternative concepts of public “third places” through the lens of speculative design artefacts. “Third places” (i.e. neither home nor work) play a crucial role in building and maintaining social infrastructures and supporting well-being. However, access to these spaces is not equally available to everyone. Older adults with limited mobility, for example, or people experiencing loneliness, may find it difficult to participate in public social life or initiate contact through conventional means. This can lead to social isolation and loneliness. Although virtual or digital third places have emerged in recent years as an alternative, they are often not designed with older users' needs and abilities in mind. This work explores how imaginary, non-physical communication spaces can be created through tangible design objects.

Lightweight design is under the premise of same material and manufacturing technology genuinely essential for sustainability and resource efficiency, yet lightweight products are often perceived as less valuable and less robust. This exploratory study investigates how product weight and shape influence perceived value, robustness, and acceptance. A within-subjects study with 35 participants examined three product types representing different usage contexts: a bottle opener, a camping mug, and a pipe wrench. Visually similar product pairs with systematically varied weight were evaluated, complemented by a second study manipulating both weight and shape. Quantitative ratings were combined with qualitative statements to uncover underlying perceptual mechanisms. Results indicate that heavier products are consistently perceived as more valuable and robust, while lighter variants are associated with lower price expectations. Weight differences based on the Weber–Fechner law were partly insufficient to produce significant effects, suggesting the need for larger absolute differences. A moderate correlation between perceived value and robustness was found, while shape effects were limited primarily to robustness perception.

Automation leads to a rise of assistance systems in vehicles, machines and tools. Existing classifications classify those along processing stages and automation level. However, the purpose and the dimension of the assistance were not used as criteria yet. We propose a classification system for assistance systems by the degree of assistance with automation levels, the dimension of assistance, describing the ratio of user and assisted guidance in 3D space, and the mode of assistance, describing the purpose in terms of comfort, performance, and safety. The classification system is tested for general suitability by applying it to an established industry and one rather new to assistance systems.