Week 6 Flashcards
what is a statistical test
a way to systematically test whether a given scientific claim is valid or not
to test whether a scientific hypothesis is supported by the evidence provided
calculate the probability of obtaining the observed data if the hypothesis is true
what is a p value
the probability that your hypothesis is right
what is the threshold level of a p value called
alpha level
what is the null hypothesis
a hypothesis against the research question, claiming there is no difference in the result and the only differences observed are just noise/error
what is the research/alternative hypothesis
the opposite to the null hypothesis claiming that there is a difference in the result
what is a type 1 (false positive)
it isn’t correct but you conclude it is
e.g. you reject the null hypothesis when it is true
what is a type 2 (false negative)
it is correct but you conclude it isn’t
e.g. you don’t reject the null hypothesis when it should be
what test do you use for proportions with more than two levels
chi square goodness of fit test
what test do you use for comparing proportions across two or more groups
chi square test of associations
what test do you use to compare a measure with a fixed value
one sample t-test
what test do you use to compare a measure across two groups
independent: two samples t test
paired: paired t test
what test do you use to compare a measure across more than two groups
ANOVA
what is a chi squared test
- a test of difference among categorical (nominal/ordinal) variables
- goodness of fit: how the proportions in data fit to fixed proportions
- test of association: how proportions of two data sets are associated
what does df stand for
degree of freedom
sample size-number of groups
what is benfords law
the frequency of first digits of naturally occurring numerical data follow a particular proportion
