1Radom sample
a sample such that each member of the underlying population has an equal probability of being selected.
2Population
data for every possible realveant case
3Confidence interval
a probabilistic statement about the likely value of a population charterisitc based on the observation in the sample
4Statistical significance
the relationship between two varribales is not due to radom chance and therefore exists in the boarder population
5Normal distburtion
a bell-shaped statistical distburtion that can be entirely charterzied by its mean and standard deviation
6Standard error
the standard deviation of the sampling distribution of the sample mean.
Inference- the process of using what we know about a sample to make probabilistic statements about the border population
7Difference of means
a method of bivarriate hypothesis testing that is appropriate for a categorical independent varribale and a continuous dependent varribale
8Correlation
measure of linear association between 2 continuous varribales
9Null hypothesis
predicts no relationship between the varribales
10Omitted-varribale bias
specific type of bias that results from the failure to include a varribale that belongs in the regression model
11Standardizing coefficients
regression coefficients such that the rise-over-run interpretation is expressed in standard deviation units of each varribale
12Perfect multi-collineary
when there is an exact linear relationship between any two or more of a regressions models independent varriable
13Dummy variable
a varribale that takes on one of two values usually 1 or zero
14Probability
probablilty of an event is the number of times that event can occur relative to the total number of times any event can occur.
15Properties of probablilty
The probability of an event is between 1 and 0
If the events can not occur simultaneously then p is the sum of the event probabilities
Probability that an event will not occur is 1-p(event)
Sum of probabilities from all possible events is 1
16Independence
two events are independent if the chance of one event occurring is not affected by the outcome of the other event.
17Rules of probability
1. Addition rule for mutually exclusive events -p. (outcome 1 or outcome 2) = p(outcome1) or p(outcome2)
2. Complement rule: -p(not outcome 1)= 1-p(outcome1)
3. Multiplication rule for independent outcomes- -p(outcome1 and outcome2)= p(outocme1 x P(outcome 2)
4. Multiplication rule for dependent events
18How to determine statistically significance
Perform a hypothesis test
Start with null hypothesis
19what assumptions to make when calculating proabablilty
There is no difference between treatments
What the probablility distrubution is
20If the null is 1 out of 20
reject it
21Statisicial inference
is the process of making probabilistic statements about a population characteristic based on our knowledge of the sample charterisitic.
22Outcome
result of radom observation
23Cross tabs
two categorical varribales
24T-test
binaryiv/ internalatio dv
25Regression
ways to measure an association between a and y where both values are at the intervalatio level of measurement
26Scatterplot
visual representation of the data on an x and y axis
27Five steps hypothesis test process
1. State the null hypothesis
2. Look at the data
3. Computing the “calculated” t
4. Calculate p-value
5. Draw a conclusion about the null hypothesis
28if the p-vlaue is less than .05
Reject the null hypothsis
29if the p-vlaue is larger than .05
accept the null hypotheis