In Lojban, therefore, shorter lujvo will be used for a less complicated concept, possibly even over a more frequent word. If two concepts compete for a single rafsi sequence, the simpler concept will take a shorter form, and the more complex concept will have some indication of its more complex nature added into the word structure. It is easier to add a cmavo to clarify the meaning of a more complex term than it is to find a good alternate tanru for the simpler term. If someone hears a word he doesn't know, decomposes it, and gets a tanru that makes no sense for the context, he knows that the grouping operators may have been dropped out, he may try alternate groupings. Or he may try using the verb form of the concept instead of the first sumti, inserting an abstraction operator if it seems plausible.
Plausibility is key to learning new ideas, and evaluating unfamiliar lujvo.