HCI STUDY
The Design of Everyday Things
This week's study range: pp.77-108
Scheduled for Saturday, 2012.10.20
1. Accurate action based on imprecise knowledge
It is easy to show that there are errors in a person's knowledge and memory.
(Rather than calling it "error," it might be better to say that the priorities that prompt user action can differ —
that would reduce room for misunderstanding.) (Example: computer keyboard)
For the following reasons, accurate action becomes possible despite imprecise knowledge.
(This judgment seems to assume that the cause of user action is knowledge. Personally, in fact
people act based on what they know less often than they act otherwise.)
In everyday situations, action is determined by the combination of internal knowledge and external information and constraints.
(= Users act within what they know (knowledge), but for the parts they do not know, they act by inferring from the surrounding situation
.)
If information can clearly be obtained from the environment, then the accuracy of information that must be stored in memory only needs to be enough to maintain the quality of the intended action — so accurate action is possible even on the basis of imprecise knowledge.
People live by using two kinds of knowledge. One is knowledge about "what," and the other is knowledge about "how." Knowledge about "what" is declarative knowledge — things you can usually handle by memorization; knowledge about "how" is called procedural knowledge, and because it is subconscious, it is knowledge that can only be gained through demonstration by a teacher and one's own repeated experience.
Let us think about what it is that we must remember in this convenient world. (zip codes, addresses)
Let us also ask whether those things we memorize are being used as codes for the convenience of machinery.((find examples))
Psychologists classify memory broadly into two types: short-term memory and long-term memory.
Generally, it takes time and effort to put something into long-term memory and then pull it back out. For this reason, we do not remember the accurate record of events we have experienced; rather, we store what we have interpreted based on our understanding of them. In other words, what matters in long-term memory is not capacity but organization. That is, how to put content in and pull it out. Storage and retrieval become easier when the memory's content has meaning or fits what we already know. When the content lacks meaning, it can only be stored after it is processed, structured, and interpreted.
Types of how people use their memory and retrieve information
1. Memorization of arbitrary things. The items to be retained are arbitrary, have no meaning, and appear to have no specific relationship to other items or to what is already known.
1-1) It could be said to be simply memorizing what must be done, without any understanding of its cause, reason, or internal structure. (The alphabet, multiplication tables, many procedures we learn in order to use modern technology.) This kind of mechanical memorization causes problems. 1) Memorization demands significant time and effort. 2) Because one does not understand the reason for one's own actions, it is hard to respond efficiently when an exceptional situation arises.((find examples))
2. Memorization of meaningful relationships. The items to be retained have meaning in themselves or form meaningful relationships with other already-known things.
2-1) Most things form meaningful structures. For something to have meaning is for it to correspond with the knowledge we already hold, so that new content too can be understood, interpreted, and integrated with what we have previously acquired. Through meaningful structure, we can organize things that seem chaotic and arbitrary.
The power of a good mental model lies in its ability to give events meaning. Let us take an example where, by bringing in a meaningful interpretation, what looked like a surface-level arbitrary task changes into something natural.
((find examples — there are probably cases similar to or applying educational methods.))
3. Memory through explanation. The content need not be remembered; rather, it can be derived from another explanatory mechanism (method).
3-1) Let us handle a stronger form of internal memory — namely, understanding. Explaining and interpreting an event is fundamental to the human behavior of understanding, learning, and remembering this world. Here, mental models play an important role. Mental models simplify learning — one reason being that the details of needed action can be derived through them. They also play a valuable role in coping with unexpected situations.((iPhone? touch-point case study?))
Mental models help derive appropriate action in situations where memory does not exist (we have not experienced it). Most people build a mental model for what they do.((This seems similar to a person's values.))
Because if an appropriate mental model is not provided, people will build one themselves — even an inappropriate one.((each person's experience of an inappropriate mental model))
2. Memory is also in the world.
Knowledge in the world (external knowledge) is very valuable. But if the environment is not appropriate or if conditions change, key memory support disappears, and tasks or certain details may not be remembered.((Case study — the Eclipse program, suddenly thinking of something on the subway..?.. I did not bring my watch so I forgot to think of A. I did not think to check my daily email and forgot an important appointment...?))
Reminding : One of the most important and interesting aspects of the role of external memory is reminding(reminding)인데, , which is a good example of the interaction between knowledge in the head and the world. One good method of reminding is to place the burden on the object itself. ((each person's personal methods of remembering?))
Reminding has two aspects: the signal and the message. Just as, when about to act, we can think about what to do and how to do it , in reminding we can distinguish between knowing that we must remember something and remembering what it is . For example, "tie a string around your finger" only provides a signal. Ideal reminding must carry both elements — a signal that something must be remembered, and a message about what it is.
(( 1. alarm clock, notebook, calendar,, 2. And 5-6 years? — written in 1996.. did this predict iPhone apps? ^^ 3. If we try to predict something next? ))
Natural mapping : Examples like the layout of stove burners or oven switch placement — designs that rely on labels are wrong. Labels are sometimes important and necessary, but if natural mapping is used well, labels can be minimized. Whenever a label looks necessary, look for another design. ((Honestly I cannot fully agree. Around us, we often see cases where, because of a designer's overreach(?), users suffer a lot of inconvenience over things that a single label could have solved. What do others think? ))
For ease of use, the suggestion is that users not just look at a product from the outside but actually use it. However, there are cases where that does not happen, and the opportunity is stripped away by an intermediate supplier's arbitrary choice.
( -> This part, in chapter 6 )
Trade-offs between knowledge in the world and knowledge in the head:
Knowledge in the world : Whenever it can be seen or heard, learning is unnecessary; interpretation alone is enough..(쉬운해석 = Natural mapping 관계와 제약의 효율적 활용), Time taken to find and interpret external information; easy to use. May not be aesthetic or elegant. (Especially with many features.)
Knowledge in the head: Memory has to be searched or recalled. Sometimes requires considerable learning..(The subject can reduce learning difficulty through meaning structures or good mental models.) Very efficient and immediate response is possible. Hard to use. Since nothing needs to be shown or explained, the designer can exercise more of their own capability.
