# W8 - Effect Size Flashcards

What do inferential statistics allow us to do?

Make conclusions about the pop based on sample statistics

What can be HIGHLY influenced by the sample size

The p-value

Therefore whether the data shows it as being statistically different or not/

Explain sample size + statistical significance

Very large sample size = Possible to get a significant effect when the real effect is very small

What does a larger sample size result in for the representativeness of the sample of the population

Larger sample size = More representative the sample of the pop

Larger sample size = More representative the sample of the pop

What follows?

Lower risk of sampling bias = ⬆️ reliability from a small effect

Why is an effect size created?

To determine whether something is PRACTICALLY significant + meaningful in the real world.

What can effect size facilitate with?

Comparison of effect across studies

What is an estimate of effect size?

Correlation coefficient (r)

What can Cohen’s D be used for?

To look at whether the difference between the 2 means of 2 groups is meaningful or not.

When would you use Cohen’s D?

When focus is on difference between 2 means

Cohen’s D equation

D = (M1-M2) / SD

What can the SD in the Cohen’s D equation be?

Pooled = SD in total sample

OR

SD of control group / condition

In what ways can we interpret the Cohen’s D size?

In terms of small, medium or large effect

Small effect size for the r value and the D value

r = 0.1

D = 0.2

Medium effect size for the r value and the D value

r = 0.3

D = 0.5