of participants in the survey. $$\operatorname{attrakdiff}(\mathbf{x}, \,g) = \frac{1}{7 \cdot S} \sum_{s} \sum_{i} \mathbf{x}^g_{s,i}
    \label{eq:attrakdiff_score}$$ Therefore, a neutral participant would produce an score of four. The final averaged score of each group $g$ ranges from one (worst) to seven (best rating).

An overall evaluation of the results can be conducted in the form of a portfolio representation [@hassenzahl2008user]. is the mean of a system’s and scores. [PQ]{} and [HQ]{} scores of a specific system and user are visualized as a point in a two-dimensional graph. The $95$% confidence interval is an estimate of plausible values for rating scores from additional study participants, and determines the extension of the rectangle around the described data point in each dimension. A small rectangle area represents a more homogeneous rating among the participants than a larger area. If a rectangle completely lies inside one of the seven fields with associated adjectives defined in [@hassenzahl2008user], this adjective is regarded as the dominant descriptor of the system. Otherwise, systems can be particularized by overlapping fields’ adjectives. If the confidence rectangles of two systems overlap in their one-dimensional projection on either or , their difference in scores in regards to this dimension is not significant.

Qualitative Measures 