# Cumulative Impact of Testing Factors in Usability Tests for Human-Centered Web Design +
## 7 Conclusions  
### Further Discussion of the Results  
Our work has shown that factors that affect user performance in solving web design-related tasks have to be assessed complexly, as individual assessment of single factors does not explain the effects discovered by earlier literature, or such effects may be conditioned by more factors than described in literature. We have shown that co-assessment of the 'contextual fidelity model' factors demonstrates divergent patterns of their cumulative impact, where previously effects were considered one-dimensional. This approach may have greater explanatory power when effects do not correspond to expectations. Extending our previous work on the contextual fidelity factors [18; 22; 28], we have linked it to the activity theory that provides for complex understanding of user reactions to multi-factor stimuli from the functional viewpoint, as it sees resulting user states as complex (intellectual + emotional) and (dys)functional, which actually describes the user states researched upon in DUXU but does not name them properly. In our interpretation of the contextual fidelity factors, we have chosen the way opposite to the most research designs that orient to narrow and single proxies for each model factor. In contrast, we have used the U-index that includes 13 other parameters for product features, state-inducing rather than imitational tasks for task features, cultural differences as the major proxy for user traits difference, and individual/group performance as the test condition that casts most impact upon user performance. This strategy had been implemented in our previous work [28], but on much smaller data (16 vs. 80 assessors). For this paper, we have extended our sample and have also performed cross-cultural analysis, thus testing all the contextual fidelity factors in one research design; cultural differences, though, did not play any substantial role in how user perceptions worked and how the dysfunctional states formed. This gives a hint that dysfunctional user states in user experience may have a universal character not much dependent on cultural differences, but, of course, our data are not enough to tell it for sure. We have detected two effects that have manifested within several combinations of factors, namely the monotony effect and the anxiety effect. While we, indeed, meant to induce these effects, we did not know which combinations of factors would lead to them, and which features of mental/emotional states would be responsible for them. We have shown that these effects may have cumulative nature--that is, they may grow when combinations of factors change. We have shown that they may also have antagonistic nature, going against expectations in terms of what factors compensate the negative cumulative effects. There were also signs of effects that need further investigation, namely, the hyperlability effect in the state of anxiety forming on low-quality web pages and the nearly-significant cultural differences in formation of excitement. As to the impact of individual contextual fidelity factors within cumulative effects of dysfunctionality, we have shown that the testing environment plays a leading role in usability performance, as the results of the study confirm its influence on nearly any combination of other factors. Undoubtedly, other contextual fidelity factors also turn out to be significant for cognitive performance and emotional states of users. At the same time, the significance of these factors is unequal. Thus, in the proposed study, the next in importance after the individual/group format is the type of task. In particular, in the formation of anxiety, the cumulative effect is observed regardless of the aesthetic quality of the product. To the greatest extent, this effect affects intellectual ability. Anxiety that is implied by the nature of such tasks is the most destructive for the users' cognitive efficiency.