Psychology Chapter 3: Similarity of Senses

Study Notes

Identity of senses refers to the relationship between two words that have the same meaning, such as "Rich" and "Wealthy".
Synonymy is the relationship between two words that have the same meaning, but not necessarily the same connotation.

Two words are synonyms if they can be replaced with each other in a sentence without changing the meaning.
There are two tests for synonymy: replacement and mutual inclusion.
Synonymy is not always complete, and it's dependent on the basic meaning of the words.
Synonymy is a mutual relation between two words, and it's not limited to words with exactly the same meaning.
Synonyms must belong to the same part of speech, except in some cases where a verb can be synonymous with a noun.

A paraphrase is a restatement of a sentence or phrase that has the same meaning as the original.
There are two ways to form paraphrases: using synonymy and using transformation.
Paraphrases are always equally true or false, and they have the same truth value.
Paraphrases have a mutual relation, meaning that if S1 is equivalent to S2, then S2 is also equivalent to S1.

Hyponymy is a relationship between two words where one word is a kind of the other, such as "Lion" and "Animal".
The higher-level word is called the superordinate, and the lower-level word is called the hyponym.
Hyponymy is a one-direction relation, meaning that a lion is a kind of animal, but an animal is not a kind of lion.

Entailment is a relationship between two sentences where one sentence implies the truth of the other.
The truth of the first sentence entails the truth of the second sentence, but the falsity of the first sentence does not entail the falsity of the second sentence.
Entailment is a one-direction relation, meaning that S1 implies S2, but S2 does not imply S1.
Cumulative entailment occurs when multiple sentences are entailed, such as S1 → S2 and S2 → S3, then S1 → S3.

Synonymy and hyponymy are related, as if A is a hyponym of B and B is a hyponym of A, then A and B are synonyms.
Entailment and paraphrase are related, as if S1 entails S2 and S2 entails S1, then S1 and S2 are paraphrases.
Entailment and hyponymy are related, as if A is a hyponym of B, then A entails B.