Well, I think that much 20th century art means to express in much the way art has since the Renaissance and to be seen on its own terms. Some of it, like much literature and music since the beginning of the 20th century, may need some education in a general background of debate about aesthetic ends and that has been true at least since accurate representation was not its own end (choose your date, but certainly prior to 1900). Still, I would bet that Pollack, Stills, Frankenthaler, etc., meant their paintings to be experienced on their own terms.
It is certainly true, on the other hand, that Duchamp, Johns, Warhol, add your own names, meant to be commenting on art and artistic debate in a way that would only make sense if you knew the debate and so I would agree with Oswaldo to that extent. I guess I was saying that I see Albers in the first group of these artists and Reinhardt in the second. Works in the first group one generally judges on the terms of the work. Works in the second are meant to be judged in terms of concepts that the works may not evidently embody and may lack interest if one doesn't care about the concept or if repetition of the concept doesn't add anything new. I was thus agreeing with Jeff about Reinhardt, but not about Albers. And I would of course add that I don't think evaluation of art can have an objective basis because of the nature of what art and aesthetic apprehension are (but we've all had that argument before).