Resumen
The origin of Electronic Performance support systems was simply the need to use technology to connect knowledge resources that seemed to complement each other. In guest editor Richard Horn's particular case, he was engaged in creating both tutorials and online reference material for software companies, so it was natural to assume that end users had computers and had no other way to learn or support themselves using the software than by using what was provided with the software. He also knew that most purchasers of software did not want to spend much time learning it, but want to open the packaging, load the software, and only learn when it was necessary to do so. One software debugging product for which he was creating support materials had the ability to effectively run two programs at the same time in a single-tasking Disk Operating System environment - something one needs to do to debug programs. He used the debugging program to spy on itself and found a way to run the customer's software program while tutorials and online reference systems were running as well.

Resumen
The typical business operation has to address a variety of issues, not the least of which are rapidly changing business environments, training employees, satisfying and retaining customers. One of the responses to these challenges is the development of a relatively new type of software called Electronic Performance Support Systems (EPSS), a term that is widely used but has no generally agreed-upon definition. One can characterize an EPSS by its purpose, its design, and its development methodology. Expressions such as "just-in-time knowledge" or "delivering the right knowledge at the right time" are often used to describe EPSS. The immediate purpose of an EPSS is to support and enhance users' performance by providing them with the knowledge required by the task they are performing at the time they are actually performing the task. This knowledge can be explicit, as in the case of information retrieved from a database and delivered to the user. It can also be implicit, such as the knowledge that goes into designing a graphical user interface data entry screen that guides the users efficiently through the task they are performing.