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) ...

Data refers to numbers, characters, text, and images that you arrange in some sort of logical or meaningful way. This is categorical data without any inherent order. Examples include blood group, ...

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 ...