Understand the logic of hypothesis testing;
Be aware of the errors in hypothesis testing;
Understand and apply the concept of hypothesis testing;
Know how to report the results of the statistical test.
Hypothesis - A prediction of how our variables might be related to each other or how they may affect each other.
Inferential Statistics - This is where we are already capable of concluding whether our variables are related to one another or not, or whether our variables affect one another. - Keyword: CONCLUSION
Probability Value
P-value
The likelihood of us obtaining our pattern of results due to sampling error if there is no relationship between our variables
Null Hypothesis
Always states that there is no effect on the underlying population
Research Hypothesis -
is the prediction of how two variables might be related to each other.
Logic of Null Hypothesis Testing
to formulate a hypothesis
to measure the variables involved and examine the relationship between them
P-value
determines whether there is evidence to reject the null hypothesis
*95% - probability that the null hypothesis is true
*5% - statistical significance level / α
Alpha (α) -the criterion for statistical significance that we set for our analyses.
-if the probability of…is less than 5%, then the findings are said to be significant.
-if the probability of… is greater than 5%, then the findings are said to be non-significant.
Type I error - is where you decide to reject the null hypothesis when it is, in fact, true in the underlying population.
-REJECTING THE NULL HYPOTHESIS WHEN IT IS TRUE
-Alpha ( α )
Type II error -is where you do not reject the null hypothesis when in fact you should do because in the underlying population, the null hypothesis is not true.
FAILING TO REJECT THE NULL HYPOTHESIS WHEN IT IS FALSE
-Beta ( β )
α VS β
α – null is true, but was rejected
β – null is false, but was not rejected
WHY SET ALPHA AT 0.05?
If alpha >.05, then we are more prone to type I errors
If alpha <.05, then we are more prone to type II errors
PARAMETRIC TESTS
uses/considers the parameters (sample mean, the population mean, etc.) of the population
data must be on an interval scale (not nominal nor ordinal)
data must be normally distributed
homogeneity of variance
there should be no extreme scores/outliers
NON-PARAMETRIC TESTS
opposite of parametric tests