Stories that have been informed fully or partly by views and experiences of people around the world in response to Guardian callouts across news, politics, business, society and culture ...

Getting the most out of A/B and other controlled tests by Ron Kohavi and Stefan Thomke In 2012 a Microsoft employee working on Bing had an idea about changing the way the search engine displayed ad ...

Background Patients with heart failure (HF) frequently suffer from undetected declines in cardiorespiratory fitness (CRF), which significantly increases their risk of poor outcomes. However, current ...