Am I oversimplifying? Well of course that’s possible. However with 2 motivated parties I think they’ll find a way. The development of various creoles and pidgin languages is a pretty good indicator of how far an intelligence motivated to speak will go. And that includes if “speaking” is done with electromagnetic wavelengths, sound waves, motions or whatever.

The hard problem is that of differing technological achievements and the motivations of the species involved. It’s difficult to overstate that within Earth societies, the more technologically advanced societies have dominated the less advanced societies. That’s socially, economically, politically, militarily, religiously, biologically, and in every other way (except perhaps morally, which is a profoundly muddy situation).

Star Trek spent a lot of time of the issue of first contact and I think they identified some of the key issues. Learn the language and culture, observe your alien, try to understand their culture. Only then proceed to make contact. Lots can still go wrong.

However when the more advanced civilization has an agenda of domination (even if it’s phrased as “helping” or “educating”), then there’s little hope for the weaker species. They may survive and even prosper in the long run but the short and medium term holds only tragedy for them.

In Brazil, I understand that the government has been following a novel policy regarding contact with remote & isolated tribes. If the tribal peoples act like they don’t want to communicate, trade, or even meet, then respect their wishes and forbid contact with them within your own society.

Even within our own species languages differ greatly. Concepts exist in one language that are difficult, nigh impossible to translate into others. One language draws differentiations between concepts, even between physical realities that others do not. Not all cultures recognize the same spectrum of colors, for instance. Don’t forget that it is hugely difficult for an adult person to gain fluency in a language with which they were previously unfamiliar, even given total immersion.

Remember also that these linguistic incongruities persist even though we all share a common brain chemistry. While there are certain universals, like a distinction between nouns, verbs and adjectives that make intra-human language learning possible, we cannot take it as a given that an extra-terrestrial species would have any commonality with us in terms of communication. Their language might not make the same distinctions between parts of speech. Their language might be entirely non-verbal: a series of bio-luminecent flashes, hyper-sonic sounds or they may have a biological means of producing and hearing radio waves.

Regarding your point about careful observation and study of a civilization, I will fully concede that Science, whether human or alien, has a basic premise of observation and testing. However, a first contact situation is much more akin to a work of social science or diplomacy than to discrete science. Today’s anthropologists continue to debate on the best means to observe a culture. While there are many that favor viewing from afar, a larger number favor interaction with or immersion in that culture. Remember that those conflicting opinions are all held by human scientists that share a common frame of reference. Aliens might make an entirely novel estimation of the issue that we would never, nay, could never have thought of.

The point is that, while speculating about communication with aliens is an excellent thought exercise, it really doesn’t tell us anything concrete about how an alien civilization might actually communicate. Any such discussion is predicated on our own understanding of communication which is, in turn, defined by our biology and our experiences on this planet. A species with differing biology that emerged on a different planet might not be compatible with us at all. On the other hand, they may be very much like us indeed. We simply don’t know with any certainty.

There is certainly the possibility that a species with 1970′s level technology but possessing a different value set might not make the same determination about such a mission’s feasibility.

It’s also possible that their technological development may have been fundamentally different from ours and that our devices are simply not analogous to one another and thus any discussion of which is more advanced might, itself, be meaningless.

Point being, any alien species that we are likely to meet will probably be so different that communication will be slow and probably mathematical in nature, if it’s possible at all.