Probability Review for the final
Basic terms:
Exclusive events, exhaustive events, sample space
Dependent/independent events
Union
Intersection
Conditional probability:
Probability tables
Probab
Lessons 23: one way ANOVA
An independent samples t-test examines whether two samples were
drawn from two populations.
How can we compare the means of more than two independent
samples?
For instance, h
Lessons 14: hypothesis testing
Parameters and statistics
Parameters = population measures
Statistics = sample measures, estimate the population parameters
A statistic used to estimate a population par
- Lesson 22
t-tests
one sample t-test
The sample variance is a biased estimate of the population variance
An unbiased estimate of the population variance
When the population variance is unknown, we ca
Lessons 15: hypothesis testing
Steps in hypothesis testing
1. State the hypotheses
2. Set the criteria for a decision
3. Collect data and compute sample statistics
4. Make a decision
Step 1: State the
Lessons 16: hypothesis testing, one and two tailed tests, p-value, effect size
A research question: Is the IQ of psychology students higher than that of the
business school students?
IQ for business s
Lessons 17: hypothesis testing, effect size and power
When research reflects reality - 1
Information on psychology students IQ is
not available for the researcher!
True state
Business school
Psycholog
Lessons 18: one sample t-test; biased and unbiased estimates
In statistics, bias of an estimator is the difference between this estimator's expected
value and the true value of the parameter being est
Lessons 21: Dependent Samples t-test
T-test for dependent samples
There are two main situations where we consider samples to be dependent:
Same participants: repeated measures (improvement in marital
Lesson 19 - effect size, errors, power,
And one sample t-test
Decisions and the probability of
errors - power
TEST RESULT
H0 True
H0 True
Confidence level
1-
Type I Error
H0 False
TRUE
STATE
H0 False
Mutually
exclusive
events
Me winning an second place in a
first place
d marathon.
they
Events are mutually exclusive when they
A and B are mutually
A and B are not mutually
overlap
cannot occur toge
Lessons 20: Independent Samples t-test
Two samples t-test
The questions we have examined so far have tested whether a single
sample was drawn from a given population (H0) or from a population that
dif