The first thing any scientist does before performing an experiment is to form a hypothesis about the experiment's outcome. This often takes the form of a null hypothesis, which is a statistical ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. David Kindness is a Certified Public ...

When news breaks, you need to understand what actually matters. At Vox, our mission is to help you make sense of the world — and that work has never been more vital. But we can’t do it on our own. We ...

Hypothesis testing is a formal procedure for investigating our ideas about the world using statistics. It is most often used by researchers to test predictions, called hypotheses. The first step in ...

In the early 20 th century, Guinness breweries in Dublin had a policy of hiring the best graduates from Oxford and Cambridge to improve their industrial processes. At the time, it was considered a ...

Confidence intervals are computed from a random sample and therefore they are also random. The long run behavior of a 95% confidence interval is such that we’d expect 95% of the confidence intervals ...

What is the chi-squared test? The chi-squared test, often written as χ 2 test, is a statistical hypothesis test used in the analysis of categorical variables to determine whether observed data are ...

What is Fisher's exact test? Fisher’s exact test is a statistical hypothesis test used to assess the association between two binary variables in a contingency table and is particularly useful when ...