Hypothesis Testing Flashcards
is it true that random samples don’t led to any sampling error
NO - they DO have sampling errors
why do random samples have sampling error
because we are taking a SAMPLE of the population to study NOT the entire population so there has to be chance differences between data
what does hypothesis testing compare
data to what we would EXPECT to see if a null hypothesis was TRUE (don’t reject)
when is a null hypothesis rejected
if the data is TOO UNUSUAL compared to what we expected from if the null hypothesis was TRUE
what phrase is associated with parameter estimation
how large the effect is and what is the uncertainty
what phrase is associated with hypothesis testing
whether there IS an effect
why are null hypothesis made
for the purpose of ARGUMENT
what view embodies null hypothesis
skeptical point of view
what is the null hypothesis FREQUENTLY based as
the population parameter has ZERO interest (ie. there is no effect, no correlation or no difference)
what happened to reject the null hypothesis (what kind of result)
an interesting result (ie. there was an effect, was a difference, was a correlation)
what hypothesis is paired with null hypothesis
alternative hypothesis
what does the alternative hypothesis represent
ALL the other parameters EXCEPT those stated by the null hypothesis (ie. there is an effect due to this parameter)
what hypothesis is tested with the data
NULL hypothesis
what hypothesis is not tested directly
the alternative hypothesis
when do we FAIL to reject a null hypothesis
when data is CONSISTENT with the expected data in null hypothesis
do we accept null hypotheses
NO
when do we reject null hypotheses
when data is NOT consistent with expected results in null hypothesis
if we reject the null hypothesis what is accepted
the alternative hypothesis
how does rejecting the null hypothesis help us identify the population parameter
helps identify which direction (according to alternative hypothesis) the true value of the parameter is
what steps are done in the hypothesis testing
- state the hypotheses (both alternative and null)
- determine the test statistic
- determine null distribution
- quantifying uncertainty (based on p value)
- determining statistical significance
what does a two sided test mean
an alternative hypothesis has two outcomes to reject the null hypothesis
(ie. if null says expectation is for data to be equal, alternative can reject it by having data greater than or less than that value)
what is the test statistic
a number calculated from the data that is used to evaluate compatibility of the results from null hypothesis expectation
(ie. if 14 of 18 frogs were right handed with 4 being left handed and the study was about proportion of righthand frogs than 14 is test stat)
null distribution
the sampling distribution of outcomes for a test statistic based on null hypothesis being true
what is the aim for a hypothesis test
to know how unusual our results are compared to the null hypothesis