Aesthetics and usability
“The importance of beauty, which we now refer to as “aesthetics”—of man, nature, or artefacts—has been recognized since antiquity. Vitruvius, the first systematic theoretician of architecture (1st Century BC), counted beauty among architecture's three basic requirements (Kruft, 1994).” 
Lavie and Tractinsky (2004)  found that “found that [perceptions of web site aesthetics] consist of two main dimensions, which we termed classical aesthetics and expressive aesthetics. The classical aesthetics dimension pertains to aesthetic notions that presided from antiquity until the 18th century. These notions emphasize orderly and clear design. The expressive aesthetics dimension is reflected by the designers’ creativity and originality and by the ability to break design conventions. While both dimensions of perceived aesthetic are drawn from a pool of aesthetic judgements, they are clearly distinguishable from each other.”
Intentions to use and use a technology or web site depends on perceptions of usability, utility and aesthetics, mediated by task types and external variables.
Interactions between usability, utility and aestehtics do not seem to be consistent accross studies. E.g. Hassenzahl (2004) found that  in two studies, “showed beauty to be rather related to self-oriented, hedonic attributes of a product than to its goal-oriented, pragmatic attributes.”. Lavie and Tractinsky (2004)  argued that “that the classical aesthetics dimension is more closely related to perceived usability relative to the expressive aesthetics dimension.”. Maity et al. (2015)  state “that It has been found that the perceived appeal (or aesthetic) of an interface plays important role in determining its usability.”
- ↑ 1.0 1.1 1.2 Lavie, T., & Tractinsky, N. (2004). Assessing dimensions of perceived visual aesthetics of web sites. International journal of human-computer studies, 60(3), 269-298. http://www.sciencedirect.com/science/article/pii/S1071581903001642
- ↑ Hassenzahl, Marc. "The interplay of beauty, goodness, and usability in interactive products." Human-Computer Interaction 19, no. 4 (2004): 319-349. http://dl.acm.org/citation.cfm?id=1466561
- ↑ Maity, R., Uttav, A., Verma, G., & Bhattacharya, S. (2015, December). A Non-Linear Regression Model to Predict Aesthetic Ratings of On-Screen Images. In Proceedings of the Annual Meeting of the Australian Special Interest Group for Computer Human Interaction (pp. 44-52). ACM. http://dl.acm.org/citation.cfm?id=2838743
- Ben-Bassat, T., Meyer, J., & Tractinsky, N. (2006). Economic and subjective measures of the perceived value of aesthetics and usability. ACM Transactions on Computer-Human Interaction (TOCHI), 13(2), 210-234. http://dl.acm.org/citation.cfm?id=1165737
- Cai, S., Xu, Y., Yu, J., & De Souza, R. (2008). Understanding aesthetics design for E-commerce web sites: a cognitive-affective framework. PACIS 2008 Proceedings, 60. http://aisel.aisnet.org/cgi/viewcontent.cgi?article=1165&context=pacis2008
- Hassenzahl, Marc. "The interplay of beauty, goodness, and usability in interactive products." Human-Computer Interaction 19, no. 4 (2004): 319-349. http://dl.acm.org/citation.cfm?id=1466561
- Lavie, T., & Tractinsky, N. (2004). Assessing dimensions of perceived visual aesthetics of web sites. International journal of human-computer studies, 60(3), 269-298. http://www.sciencedirect.com/science/article/pii/S1071581903001642
- Tractinsky, N. (2011). Visual aesthetics in human-computer interaction: Justification and findings. DHRS2011, 1.
- Tractinsky, N., Cokhavi, A., & Kirschenbaum, M. Using Ratings and Response Latencies to Evaluate the Consistency of Immediate Aesthetic Perceptions of Web.
- Tractinsky, N. (2004). A few notes on the study of beauty in HCI. Human–Computer Interaction, 19(4), 351-357.
- Xu, Y. (2008). Understanding aesthetics design for e-commerce web sites: a cognitive-affective framework. PDF (Research Gate)