Many of the virtual assistant services use artificial intelligence, a branch of computer science that simulates intelligent human behavior. Some respond to questions posed by travelers, either in live speech or digitally, while some, like Pana, rely on additional input by humans to provide answers. Although many services are now in their infancy, they are expected to change the way travel is planned in the not-too-distant future. The Pana app lets users chat, in conversational language, about booking travel and helps if they encounter a delay or cancellation. Responses are provided by a team of travel agents who are on duty round the clock and have access to artificial intelligence to gather information customized for the traveler. Get the full story at The New York Times