Question

A researcher conducts a study of perceptual illusions under two different lighting conditions. Twenty participants were each tested under both of the two different conditions. The experimenter reported: “The mean number of effective illusions was 6.72 under the bright conditions and 6.85 under the dimly lit conditions, a difference that was not significant, t(19) = 1.62.”

Explain this result to a person who has never had a course in statistics. Be sure to use sketches of the distributions in your answer.

Answer 1

@campbell_st

Answer 2

sorry... I'm really rusty at stats... and only vaguely remember student t tests

Answer 3

Ok thank you

Answer 4

@ganeshie8 @YanaSidlinskiy

Answer 5

Hmm...This is so challenging and I really don't know it..sorry..I suggest maybe ask @tkhunny or @Preetha

Answer 6

Draw a normal curve. Make the tails nice and fat. Mark off some symmetrical region around the mean. Discuss the Empirical Rule concerning how differences might happen just be chance.

Answer 7

Can you give me an example?

Answer 8

Did you draw the normal curve?
Did you make the tails kind of fat?
Did you mark off a symmetrical region around the mean?

Draw that and we can talk.

Answer 9

I don't know how to draw it.. I never have. I'd actually be the person who they are talking to in this article lol

Answer 10

You've never seen a Normal Curve. I find that hard to believe.

Answer 11

Just a bell curve?

Answer 12

That?

Answer 13

@mathstudent55
@sourwing

Answer 14

That's it. Now, add the Mean - right down the vertical middle.