1.3 Issue of Understandibility

It is believed that different manual scopes suit users with different knowledge levels. The scope of the manuals and the users knowledge level are two dependent issues of the manual representation.

For example, manuals serving users with lower knowledge level cover real examples, background support, and fundamental explanations while the manuals serving users with higher knowledge level cover abstract concepts and mathematical equations. There is no universal manual scope standard to satisfy all the application purposes.

In summary, manual representation varies in term of the issues of media, scope and users knowledge level. The electronic media could be better than the paper media in some sense. There is, unfortunately, no perfect manual scope because the knowledge levels of the users vary. For one machine, we can design manuals with many different representations. A representation suits a particular class of users and has certain features. A new environment can possibly challenge a representation and may turn down the use of that representation. The features of a representation can satisfy one class of users but not another. An expert will find that a primary level manual wastes his time while a kid will be annoyed when he/ she needs to go through a very technical manual of a toy. Besides a person who does not have computer knowledge may have difficulty in using the online help and a person who loses the paper manual will become helpless when he needs to refer to it some times later. As a representation restricts the use of a manual in certain areas, we can draw a conclusion that there is no universal manual representation that can satisfy all using constrains.