# The Human-Centredness Metric: Early Assessment of the Quality of Human-Centred Design Activities
## 3 Results
### Assessment of Concepts  
The 16 concepts, consisting of requirement lists, functional structures, sketches, and descriptions, were evaluated with each item of the metric from Section 2.2 using a 4-point Likert scale. The response options were as follows: probably fulfilled, rather fulfilled, rather not fulfilled, and probably not fulfilled. If no statement could be made about the probable fulfilment of the item, \"not applicable\" was selected. In order to improve the comparability of the product concepts, a product group was always evaluated in one instance when evaluating the concepts. This means that all washing machines were evaluated first, then all vacuum cleaners, etc. Figure 5 graphically shows the results for the HCM score for all 16 concepts sorted by the methods used, i.e., concepts created with the same methods are grouped together. The order within the blocks of four from left to right is always first washing machine (WM), then vacuum cleaner (VC), then Blu-Ray player (BRP), and finally coffee machine (CF). This  
Figure 4: Examples of resulting concepts consisting of sketches and additional information. means that, for example, the second column in the fourth block of four, \"+M3: Dialogue Principles\", shows the results for the vacuum cleaner concept, which was developed with the help of the general approach to design (M0) and the Dialogue Principles (M3). The sorting therefore does not directly give any information about the participant who developed the concept or the order of development. For this, an examination of Figure 3 is necessary. Accordingly, in this example, the vacuum cleaner concept with the additional method M3 was developed by the fourth participant as the fourth concept in the row. The individual results are shown as a stacked bar chart. This can be read as follows: approximately 54% of the items for the washing machine concept without an additional human-centred method (first column of the first block of four) were rated as probably fulfilled (dark blue); another approximately 30% as rather fulfilled (light blue); approximately 15% as rather not fulfilled (light red); approximately 2% as probably not fulfilled (dark red); and 0% as not applicable (grey). In addition, the mean values (horizontal lines) and the standard errors of the mean values (vertical lines) are plotted for each group of four. For example, the mean value of the probably fulfilled items of all four concepts for which the Universal Design Principles were used as an additional method (second group of four) is 65.3% and the standard error of this mean value is 8.5%. Figure 5 provides a good visual representation of trends in the added value of human-centred approaches. Here, one can directly see that the concepts that emerged with additional methodological support had overall higher mean values with regard to the number of probably fulfilled items. That means that the dark blue horizontal for the three right groups of four (+M1, +M2, +M3) always higher than the dark blue horizontal for the first group of four on the left (M0). In the same way, the proportion of items that are probably not fulfilled is always smaller than on the left. That means that the distance between light red and dark red horizontals for the three right groups of four (+M1, +M2, +M3) is always smaller than the same distance for the first group of four on the left (M0). However, this representation also shows the sometimes very large standard errors and tells us nothing about whether the values are significant. It is also not possible to tell whether they differ due to the change in the independent variable--an additional human-centred approach--or whether the cause is rather individual differences between the participants or learning  
Figure 5: HCM scores depending on additional design method for each concept. effects. The mean values of the concepts are therefore further checked for significance with IBM(r) SPSS(r) Statistics, version: 28.0.1.1 (14).