## 4 Performance Evaluation
### Exploring the Design of Pepita
#### 4.1.2 Results  
Table 1 refers to the huggable aspect, comparing Pepita with the other three huggable robots. One-way analysis of variance (ANOVA) was applied for each aspect and significant differences in each aspect was found (\(p<0.001\), \(\mathrm{F}(3,204)=8.94\), \(\eta^{2}=0.13\) in \"Looks huggable\", \(p<0.001\), \(\mathrm{F}(3,204)=5.92\), \(\eta^{2}=0.087\) in \"Looks easy to hug\", \(p<0.001\), \(\mathrm{F}(3,204)=17.0\), \(\eta^{2}=0.25\) in \"Looks appealing\" where \(p\) and \(\eta^{2}\) denote significance probability and effect size respectively). Afterwards, to investigate the differences between Pepita and other robots, [PERSON]'s multiple comparisons test was used as a post hoc test. As the result, the following combinations showed significant differences: Pepita and The Huggable (\(M=-0.673,\ p<0.01,\ 95\%\ \mathrm{CI}[-1.22,-0.122]\)) in the \"Looks huggable\" category, Pepita and The Hug (\(M=0.596,\ p<0.05,\ 95\%\ \mathrm{CI}[0.0414,1.15]\)) in the \"Looks easy to hug\" category, Pepita and Probo (\(M=0.808,\ p<0.01,\ 95\%\ \mathrm{CI}[0.225,1.39]\)) and Pepita and The Huggable (\(M=-0.750,\ p<0.01,\ 95\%\ \mathrm{CI}[-1.33,-0.167]\)) in the category of \"Looks appealing to hug\", where \(M\) denotes the mean difference and \(95\%\ \mathrm{CI}\) represents the \(95\%\) confidence interval. Regarding the question about the emotional expressions, each robot scored as follows: Pepita = 4.00 \(\pm\) 0.929, Probo = 2.98 \(\pm\) 1.15, Zeno = 3.44 \(\pm\) 1.04 and Buddy = 4.52 \(\pm\) 0.754. One-way ANOVA revealed that there is a significant difference among means of participants' answer for different robots (\(p<0.001\), \(\mathrm{F}(3,204)=25.4,\ \eta^{2}=0.27\)). Significant differences were found between: [PERSON] and [PERSON] (\(M=1.06,\ p<0.001\), \(95\%\ \mathrm{CI}[0.562,1.55]\)), [PERSON] and [PERSON] (\(M=0.558,\ p<0.05,\ 95\%\ \mathrm{CI}[0.0615,1.05]\)), and [PERSON] and [PERSON] (\(M=-0.519,\ p<0.05,\ 95\%\ \mathrm{CI}[-1.02,-0.0230]\)), using [PERSON]'s multiple comparison test. The box plot presented in Figure 6 shows the results of the evaluation of [PERSON]'s appearance using semantic differential. Each item refers to a pair of adjectives. The median values of the pairs Unkind/Kind, Unfriendly/Friendly, Unpleasant/Pleasant, and Awful/Nice were found to be positive (5.5, 5, 4.5, and 5, respectively). On the other hand, the pairs Fake/Natural, Artificial/Lifelike, \begin{table}
\begin{tabular}{c c c c} \hline \hline
**n = 52** & \begin{tabular}{c} **Looks Huggable** \\ **(mean \(\pm\) SD)** \\ \end{tabular} & \
\begin{tabular}{c} **Looks Easy to Hug** \\ **(mean \(\pm\) SD)** \\ \end{tabular} &
\begin{tabular}{c} **Looks Appealing** \\ **(mean \(\pm\) SD)** \\ \end{tabular} \\ \hline Pepita & \(3.21\pm 1.04\) & \(3.56\pm 1.05\) & \(2.77\pm 1.19\) \\ Probo & \(3.10\pm 1.23\) & \(3.31\pm 1.12\) & \(1.96\pm 0.96\) \\ The huggable & \(3.88\pm 0.95\) & \(3.83\pm 1.01\) & \(3.52\pm 1.18\) \\ The hug & \(2.83\pm 1.05\) & \(2.96\pm 1.14\) & \(2.42\pm 1.20\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Results of the comparison among huggable robots based on their appearance. (SD: standard deviation). and Machinelike/Humanlike were found to be negative (3, 3, and 3, respectively), and the pair Unconscious/Conscious had a neutral value of 4. After evaluating the appearance by a scale, the participants gave open-ended responses regarding those aspects that positively or negatively impacted their perception of the robot. To summarize the different answers, these were simplified using single words and grouped in categories:  
* Positive aspects (mentions): Shape (8), Projector (7), Color (7), Cute (5), Size (5), Flowers (5), Tail (4), Kind (3), Huggable (3), Interactive (2)
* Negative aspects (mentions): Scary eyes (9), Shape (7), Face (6), Texture (6), Artificial (4), Appearance (4), Tail (3), Hard (2), Not huggable (2), Quality (2)  
Among the positive aspects, the shape, color, and the projector had the strongest impact.