Pew Research Center designed this study to assess the current state of online survey sampling methods – both probability-based and opt-in – and determine their accuracy on general population estimates ...

Medical research plays a vital role in advancing healthcare, improving treatment, and informing public health policies. However, it can be difficult to understand a study or whether it is trustworthy.

An illustration of the various elements of the overall Mars Sample Return effort. Credit: NASA/JPL-Caltech LAS VEGAS — Companies selected by NASA to study alternative approaches to Mars Sample Return ...

Medical research is essential for advancing the understanding of health, diseases, and treatments. There are many types of studies that serve different purposes. Medical research, or health research, ...