It is the last article in the first big cycle of theoretical articles. Further it may become a little less regular, but definitely a new cycle will be much closer to practice.

Today we will talk about realism in a virtual reality. Often, to make the interface more convenient, it is enough to recollect how similar things are arranged in a reality. Here are some examples.

In modern interfaces often there are dialog boxes which are called each time at fulfilment of certain operation. And each time it is necessary to customise in it the same options. From time to time options may differ, but not always significantly. An example of such dialog box is dialog of burning CDs program K3B. Developers differently solve convenience problem of unchanged from time to time options. More often they implements saving of several options versions + possibility of reset of all options to defaults. If the user has not paid attention to saving feature or has forgotten to save it, at new disk burning he should restore all necessary options again.

Now we will imagine a room-workshop in which each time at enter all tools appear in its right places. I think everyone will agree that it would be extremely not convenient. In reality a thing always remain there where we have left it. And if someone suddenly rearranges it without our knowledge (for example, wife/mom/sister will put your things in order) it becomes very inconvenient.

Also with dialog boxes, it is better to leave options in such position in which they were left by the user at the last usage. And it is necessary to solve a problem of saving of various options versions also as well as a versioning files problem. So the user always can simply cancel the last changes or return to any previous version of options, including to default settings.

In the Gnome display manager (GDM) when user selects a desktop distinct from the previous choice the program asks whether "to start the selected desktop environment always", "to start it only this time" or "cancel". Such solution of developers is in many respects linked with undefined the earlier select of user before correctly entering login and password. Actually it would be better, if the previous manager of windows was always started by default. It does not distract the user with extra question and does not demand extra button pressing. To make possible a correct choice in case the user does not remember what choice was earlier, it is better to remind it already after login input (without the password). After all, the information on a used desktop environment by user hardly can be carried to confidential.

Also for reasons of realism the extremely unsuccessful is solution of modern "save file" dialogs. The fact is that all applications run in windows over a desktop. A person meaningly imagines that he is in a directory on desktop. But the dialog box allows to save a document anywhere, i.e. does not go where you supposedly be. From here often immediately after saving, a person raises the question "and where it, this file?". In unDE real user position in the filesystem will be always defined by the current document (directory) and files will always create only there. It corresponds to a state of affairs in a reality when you cannot put a subject further than on outstretched arm distance. And for fast moving between the remote directories there will be marks.

Certainly, these examples do not mean that in virtuality it is necessary to introduce limitations of the real world. But it is useful to borrow from it the ordering and to free virtual world from complexity.