This is pretty good for an older page. But this part does concern me a bit:
"Introverted Thinker - Enjoy coming to new understandings, problem-solving and logic. Independent, skeptical and critical. Appear self-absorbed while they use step-by-step logic to discover the principles and connections that underlie the overall picture."
Skeptical, maybe. Just like I (an Intuitive) am skeptical about this quote. But this idea, which I've seen before, doesn't tell the whole story. Because in my vast experience, when it comes to real life situations, Intuitives tend to be more gullible and Sensors more skeptical.
A Sensor I've known for a few years (he scored 100% on the MBTI Sensing scale) is a notorious skeptic. But he enjoys pulling the wool over the eyes of our Intuitive friend. I've done that myself. I told the Sensor how gullible our friend is for believing whatever it was I said to him, and he replied, "So what else is new?"
I realize these are only two examples, but I could go on to bring in more and more examples of Sensor skepticism and Intuitive gullibility involving various people I've known. Intuitionist skepticism only involves the intellectual realm, and probably just the introverted thinking type as these pages state.
These skeptical Sensors would no doubt score high on the Sentinel ANSIR scale, and the statistics hint that Sentinel is the most common type, just as MBTI Sensing is far more common than Intuition.