Imagine you're a researcher studying how sleep affects mood. To explore the connection, you would look at two key "variables": sleep (how much someone gets) and mood (how happy or irritable they feel) ...

A variable is an event, idea, value or some other object or category that a researcher or business can measure. Variables can be dependent or independent. Dependent variables vary by the factors that ...

Discover this money expert's factors that reveal when your retirement savings are enough -- and how to know the right time to ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Covariance indicates the relationship ...

In a new article, a team of researchers analyze how to avoid misinterpreting correlations in cross-cultural studies. The researchers identify three sources of non-independence in cultural variables -- ...

Daniel Liberto is a journalist with over 10 years of experience working with publications such as the Financial Times, The Independent, and Investors Chronicle. Robert Kelly is managing director of ...