Validity refers to whether a study measures what it claims to measure, or in other words, how truthful it is.
Validity is one of those concepts that can really tie you up in knots - the more you think about it the more difficult it can become. Don’t worry if you find it a bit confusing; most psychologists and textbooks don’t always agree about this concept, and they often use different terms and definitions. However, if you know that it simply refers to whether a study measures what it claims to measure, then you’re just about there.
