Sentence:  The differentiation however is not very much greater , as shown by the fact that Athabascan shows 3.46 stems per meaning slot as against 2.75 for Yokuts , with a slightly greater number of <WSD>languages</WSD> represented in our sample : 24 as against 21 . 
Meaning of the word marked with <WSD> tags:  a systematic means of communicating by the use of sounds or conventional symbols