How many words does a linguist need to translate a 'new" (undeciphered) language?

Question

When linguists translate a completely unknown language or script (such as ancient Egyptian or Linear B), how much "raw material" do they need? For example, the Rosetta Stone was quite lengthy and clearly provided a plentiful sample of translated words which allowed hieroglyphs to be deciphered. How small can the "Rosetta" sample be but still allow an expert to work out the entire language? Can it be done with a few dozen words?

Answer 1

Not many if they are a cunning linguist:)