From my perspective, the terms "artificial" and "synthetic" convey the same engineering meaning relative to machine learning. The intelligence of a computer system is derived from a human interpretation, model, of how one believes the learning process evolves. Since this process is bound by this constraint, any derived knowledge can be no better than the underlying algorithm that supports the process. To this end, the application has synthesized the function of the human brain's cognitive capabilities as modeled by the the algorithm. The term "artificial" or “synthetic” simply implies that the learning was done by machine.
Furthermore, I argue that Eliza or any any system that implements a similar fundamental concept are examples of how computers can be programmed to mimic the behavior of a human. I think it is very unfair to claim that Eliza is an AI system. Eliza was simply a program to dupe naive people into believing that the computer was performing an "initial psychiatric interview" with them. It did not offer any form of learning, but rather searched for key words that could be rephrased to answer/create new questions that the user would deem to be plausible. I view Eliza as a teaser to the capabilities that machine learning could offer in the future. Interestingly, I always considered Eliza to be a condemnation of psychotherapy. Based upon comments raised by my blog colleague in our offline discussions, I now recognize the adverse impact that it has had on the perception of AI.
As an engineer, I believe that a fair example of an AI system is a linear/non-linear control mechanism. Such systems are used in various applications, and using real-time data, adapt system performance to ensure that functionality and stability are maintained. A simple example of such a system is a one-step ahead controller. Examples of these systems can be found aboard ships, in machine-based automation, etc.
From many discussions that I have had with my academic peers in sociology and psychology regarding machine learning, I recognize the ongoing philosophical debate that surrounds it (i.e. artificial vs. synthetic). The bottom line is that until the cognitive function of the human brain is mapped, machine intelligence will remain an interpretative representation of this function. Philosophically, I believe that Artificial Intelligence is Synthetic Intelligence.