STAMFORD: Virtual assistants can do far more than find the nearest gas station or get the score of a big game. Now they can help users schedule their next vacation. 

Reflecting the prevalence and sophistication of artificial-intelligence services, Stamford-based travel firm Kayak has quickly expanded its use of the technology in the past two years. Among its latest innovations, it has launched hotel booking with Amazon devices featuring the voice-activated Alexa assistant.