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 ...

When it comes to study strategies, there is no “one size fits all.” You have to figure out what works best for you. That being said, there are certain steps that all good study strategies require. The ...

Biological samples can be highly susceptible to changes over time, which often occur when they are removed from deep refrigeration. Degraded samples can produce spurious results in research. To ...