Statistics Types of Tests
Z Tests (Z-scores)
SINGLE SCORE:
o Comparing 1 individual score to a population (think of this population as the "control
group" except this hypothetical population includes EVERYONE who qualifies to be in
the control group, not

Remember the concept of Hypothesis testing, when we compared one individual to a
whole population of individuals?
So what happens when we want to compare a group of individuals (sample) to the
whole population of individuals?
We couldnt just compare each

Do you know population
parameters? ()
Yes
No
Are you working with samples
or an individual score?
Are y ou comparing a single
sample (with ONE set of
scores) to a greater population
(with unknown )?
Samples
Individual
Yes
No
Distribution of Means
Hypothes

T-Tests for
Dependent Means
We are used to fitting all of our statistics knowledge into a cookie cutter template: You have one sample (it may be an
individual or a group) that you want to compare to a general population. Sometimes, this population may or

Symbols in Psychological Statistics
Mean
M = Sample Mean
= Population Mean
M= Mean of the Distribution of Means
Standard Deviation/Variance
SD = Standard deviation of a sample
= Standard deviation of a population
M = Standard Deviation of the Distributi

Whats the Difference between a Distribution of Means Test and a
Single Sample T-Test?
Both tests describe a group being compared to a larger population. But how often, in real life, do you know all
the parameters (mean, standard deviation, etc.) about you

What in the heck is a Z-Score? And why does it matter anyway?
Question: Is it better to get a 700 on your math SAT or a 33 on your math ACT?
Just looking at it for face value, we cant compare an SAT score to an ACT score. We are essentially
comparing appl

5 Steps of Hypothesis Testng
Step 1: Restate the problem as hypotheses about populations
Population 1:_
Population 2:_
Hypotheses
Null
Words
Symbol
Ho:
Research
H1:
s
Step 2: Determine the characteristics of the comparison distribution
2 OR S2
OR S
* If