Let's suppose we intercepted a message in an unknown language. We were not able to decipher it, but we were able to decode it. Meaning we know the letters but not the meaning of the words in the text. Assuming the text is sufficiently long, we now know every single letter of this language.
Can we say that based on the fact that the language uses just a few letters, it is probably simplistic and hard to use for passing complex thoughts? And if so, can we assume that the civilization using this language is probably primitive?
Or more generally, can athe number of letters in alphabet suggest how advanceadvanced the civilization is? Also, is there a practical limit to how littlefew characters canan alphabet can have to allow for some possibility of scientific progress? For example, is it OK to assume that civilization using only 10 letters is capable of space travel?
Edit:
Thanks for all the great answers! My conclusion is, that I can't assume anything about level of civilization based on their language. To address those pointing out to binary encoding of message we use, I'm aware of this and for my question I assumed that the message was decoded from binary to actual character representation. In our world it would mean I decoded a binary message and got it'sits ASCII representation. I don't know how the characters look, how they sound or what they mean but I can distinguish between them.
Thanks for your answers, I'm not sure which to pick as acceptedaccepted; they are all great.
EDIT2:
I chose to accept an answer which gave me something to think about but if you are interested in this topic, please read through all the answers as they are all great and some are very in-depth.