## 5 Results
### Robot Embodiment Design
#### 5.1.3 Robot Build  
Participants commented on the build of the 3 different robot embodiments. 2 factors in particular stood out: density (\(n=127\)) and material comparison (\(n=122\)). **Density. ** We defined _density_ as the human's appraisal of the material's bulk softness regarding the entire object (i.e., volume), including an object's ability to hold deformation, compressibility, tensile strength/stiffness. The most commonly mentioned attributes of the robot density surrounded softness (\(n=64\)), the ability to compress/squish (\(n=9\)), the padding (\(n=8\)), and hardness (\(n=16\)). In terms of softness, participants preferred that \"the robots were soft to the touch\" [PJ40], \"soft and comfortable to touch\" [PJ10], and \"soft and warm\" [PJ-23,09,15,27,39,45]. Participants perceived a soft surface as one being comfortable to touch or to be touched by. Participants often equated softness with safety: \"If they [robots] are soft, they are safer and less resistant to touch. It also reduces the risk of injury\" [PJ04]. This ties into the cushion-like aspect (ability to compress) as participants stated that the robot should be \"strong enough to withstand someone squeezing it, but yet soft enough\" [PU10], and that there would be a \"solid framework in there, but some give to it as well\" [PU35]. One participant indicated that the robots should be made of a \"solid, hard material, and only the part you touch is covered with something soft\" [PJ48], the latter referring to the padding. It is important to add that \"if it is too soft, it won't be stabilized\" [PJ20], leading to \"just the right softness\" [PJ19] being needed to accommodate comfort, safety, and stability. **Material Comparison. ** We defined _material comparison_ as when the human compares the materials to other materials regarding the robot's build. Participants referenced specific objects and materials, from car tires, to couches, to bread dough. We group them into 5 categories: Human-like, Elastomers, Metal and In-organics, Foam Elastomers, Fabric, Plastic, Plush-filled and Other. Figure 10 shows the wide variety of materials and objects to which they compared the robot. Participants want a robot that feels _human-like_ (\(n=39\)). Participants want the comfort, warmth, and \"sensation\" [PJ22] that they feel from touching another human so having \"human skin and body temperature\" would be the best for the robot [PJ-35,45]. Other participants explained that they hoped the robot would be \"comfortable to the touch like a human being\" [PJ45]. One participant added that they would \"feel more comfortable with a soft hand like a human's than a hard hand\" [PJ45]. Not only looking like a human but feeling like a human as the robot should \"be soft to mimic human touch\" [PU22] and \"actually feels like flesh\" [PU15]. Other popular and practical choices were elastomers and plush-filled objects. _Elastomers_ (\(n=21\)) and _foamed elastomers_ (\(n=19\)) return to their original shape after being stretched or compressed, and are generally thought of as having flexibility and cushioning. Participants largely named specific materials for elastomers (e.g., silicone, polyurethane, urethane, rubber), while examples or objects were provided for foamed elastomers (e.g., memory foam, pool noodles, boxing gloves); pool noodles were valued as a material because participants viewed them as being \"an ideal material, softness, and firmness\" [PU38]. Participants also named _plush-filled_ objects (e.g., stuffed animal, pillow) (\(n=4\)) which carries a similar notion of returning to their original shape as air returns after being compressed; the fiber stuffing is combed and fluffed to form a soft ball but compresses over time. Participants made comparisons to machinery (\(n=2\)) and metal (\(n=15\)), which we group together as _metal and inorganics_. Metal was overall not a favorite for participants as (\(n=7\))of these instances were negative, with (\(n=8\)) just mentions of metal with no connotation added.