SAN FRANCISCO – Google on Friday announced its "biggest leap forward" in years in its search algorithm, offering an unusually detailed public explanation of its secret formula. The world's most popular internet search engine said its latest refinement uses machine learning to improve how it handles conversationally phrased English-language requests. "We're making a significant improvement to how we understand queries, representing the biggest leap forward in the past five years, and one of the biggest leaps forward in the history of search," Google search vice president Pandu Nayak said in an online post. The California-based internet company last year debuted a neural network-based technique for processing "natural language." The company said the new effort is based on what it calls Bidirectional Encoder Representations from Transformers (BERT), which seeks to understand query words in the context of sentences for insights, according to Nayak.