The proliferation of gadgets, apps and Web-based information has given clinicians—especially young ones like Dr. Rajkomar, who is 28—a black bag of new tools: new ways to diagnose symptoms and treat patients, to obtain and share information, to think about what it means to be both a doctor and a patient. And it has created something of a generational divide. Older doctors admire, even envy, their young colleagues' ease with new technology. But they worry that the human connections that lie at the core of medical practice are at risk of being lost. "Just adding an app won't necessarily make people better doctors or more caring clinicians," said Dr. Paul C. Tang, chief innovation and technology officer at Palo Alto Medical Foundation in Palo Alto, Calif.