Nirva is a new wearable that uses sensors and AI to analyze your mood and relationships. I look at what it actually does, how ...

Objective To determine the effectiveness of physical activity interventions involving mobile applications (apps) or trackers with automated and continuous self-monitoring and feedback. Design ...

The chart below tracks President Donald Trump’s approval and disapproval ratings across polls. It includes all national-level results on this question which meet CNN’s standards for reporting.