Distinguishing Accuracy Reliability and Validity
Accuracy
This one is self explanatory, ask yourself the question: were your results precise?
Reliability
Ask yourself: did you keep getting the same or similar results?
Reliability is how consistent your results are, disregarding the accuracy.
The big point to remember here is that your results may not be accurate but you kept getting the same results. In other words, your results may be reliable but not necessarily accurate.
Validity
This one is the one that most people have difficulty defining.
Ask yourself: Were you doing what you said you were doing in the aim?
Validity disregards accuracy and reliability, and is an indicator of whether you actually perform the experiment/procedure.
There are many examples, i will explain these terms in the example of golf:
Scenario 1: You hit the ball numerous times and they all land in a corner area of the green. Therefore you are not accurate, however you are reliable because you kept hitting the ball in the same spot, and your procedure was accurate as you actually hit the ball, lol.
Scenario 2: You are putting the ball for a eagle, it goes in the first time. You get really excited and wanna replay the shot (aka mulligan in golf). You putt it again and it goes in again. You continue replaying the ball from the same position. In this scenario, you are accurate since you have putted the ball in successfully, you are reliable since you kept getting the ball in, and you are valid, since you putted the ball every time.
Scenario 3: There is a strong gust. You put on thick clothes to keep warm and the strong winds affect the ball's flight. You hit the ball and it flies out of bounds. You hit another and it lands in the rough zone. You hit a third and it lands in a bunker. Finally after numerous shots, you finally get one on the fairway. You are not accurate because you've hit the ball all over the place, you are not reliable as you have produced shots that have landed in random places, but you are still valid since you hit the ball with a golf club properly.
Scenario Xtreme
: Your ball lands 1x10
-99cm away from the hole and you just wanna tap it in with your foot so you do that. The ball goes in. You are accurate because the ball went in, you can't say much about reliability yet since you have only performed the step once, and you are NOT valid because you didn't use the club to hit the ball in. Golf is about using a club, not your foot.
My physics teacher taught me this. Get to know these terms well as you may encounter them sometime in a nearby assessment.
