Note: Some of are FAQs list this as a philosophical question, however it is also a scientific question.
The Long Answer:
An intelligent agent (IA) has a mind. Mind that are capable of choice. IAs can be confronted with a problem, and act with purpose to solve it. Intelligent agents can mentally figure out how to solve a problem before taking any action. They can do this because they have choice-they can choose from a range of competing possibilities to choose the one which will solve the problem. This allow them to generate complex scenarios which are specified to solve a problem.
It is often claimed that in order for ID to be considered scientific, one of the things it must do is state who is/are the (IAs) as well as how they operate. Actually, it is not necessary for ID to specify the designer(s), nor how they operate. ID never claims to know the designer(s). While ID does not specifically address how IAs operate, ID does claim we can detect artifacts of IAs. In other words, all ID claims is that we can detect design. ID would say that IAs operate to take many disparate objects and construct them in such a fashion to achieve a particular goal that these components could not achieve without external input (i.e. chance and laws are insufficient to produce what is seen) - the specifics of how something was constructed may not be addressed. But this would in at least some oblique way address the issue of how design is implemented.
This allows us to make specified complex information a prediction of design.
Philosophical / Religious / Theological FAQs: