A sememe consists of a class of semantically related semes [...]
- Nida (1951), a pag.7-8

In employing the statement 'a class of semantically related semes', we have purposely avoided the expression 'common denominator of meaning'. The difficulty with the expression 'common denominator' [...] is that in a series of contexts a word may have practically no common denominator, and yet the series exhibits obvious relationships.
- Nida (1951), a pag.9

Tho native speakers may decide with relative ease as to whether or not they regard forms as semantically related, they often experience great difficulty in stating the manner in which such forms are relatable. It is at this point that the linguist may describe and classify the various relationships.
- Nida (1951), a pag.10