Two crucial ideas act as foundation for Mark Weiser’s article The Computer for the 21st Century : First, “the most profound technologies are those that disappear.” (page 94) Second, “whenever people learn something sufficiently well, they cease to be aware of it.” (page 94) I’m going to examine the latter one here.
I am unable to agree with Weiser’s statement, though I can see where he comes from. According to the example of street sign he provides afterward and what he believes as “only when things disappear in this way are we freed to use them”, I can tell that he is considering about those objects that work as “tools” or “media”. He believes that tools can serve people well when they “disappear”. This underlying idea works for objects as street signs because these objects are relatively simple and the corresponding tasks they are trying to achieve is also simple (street signs show information about streets). Thus, this idea may not work when the level of complexity increases for either the object or the task. For instance, color pencil, which is a simple tool for drawing, can be used in several different ways when being operated by an experienced painter, such as burnishing and impression. Under this situation, one actually needs to be aware of the pencil to be able to achieve distinct effects, because how the pencil is used affects the result of drawing directly. I therefore argue that depends on the complexity of both the object and the task, people either increase or decrease their awareness about this object, when they learn something sufficiently well.
The problem is: how shall we take advantage from this different degrees of awareness wisely? In ubiquitous computing, this question can be hard to answer. I would like to say that this really depends on the type of things and what they are trying to achieve, but I have no idea on the criteria of categorizing things, if any. Rogers says technologies can be engaging in UbiComp , but she doesn’t offer a good reference for researchers to judge the type of technology here. I can see the possibility for this issue to become even more complicated as UbiComp technologies are used by different people with different cultural backgrounds. Should technology be engaging when its user doesn’t value engagement much? More similar questions can be posted.
I’m not going to try to answer any question here. But I would still love to say again that we, no matter as researchers or practitioners, should place human in a central role when designing technologies. Only by designing technology in a human-centered sense can we be aware of the diversity among both people and situations. There is no universal design. Maybe it doesn’t really matter if technology is calm or engaging. Human matters.
 Mark Weiser. 1991. The Computer for the 21st Century. Scientific American 265, 94 – 104. DOI: http://dx.doi.org/10.1038/scientificamerican0991-94
 Yvonne Rogers. 2006. Moving on from Weiser’s Vision of Calm Computing: Engaging UbiComp Experiences. In Proceedings of the 8th International conference on Ubiquitous Computing (UbiComp ’06). Springer-Verlag Berlin, Heidelberg, 404-421. DOI:http://dx.doi.org/10.1107/11853565_24