With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: On May 1, 1918, Jack Paar was born.
text_B: Discounted cumulative gain -LRB- DCG -RRB- is a measure of ranking quality .. In information retrieval , it is often used to measure effectiveness of web search engine algorithms or related applications .. information retrieval. information retrieval. web. World Wide Web. search engine. search engine. Using a graded relevance scale of documents in a search-engine result set , DCG measures the usefulness , or gain , of a document based on its position in the result list .. graded relevance. Relevance ( information retrieval ). The gain is accumulated from the top of the result list to the bottom , with the gain of each result discounted at lower ranks .
not_related.