stats comp review Flashcards
(21 cards)
What is a p-value?
the probability of obtaining the data (or the data showing as great or greater difference from the null hypothesis) if the null hypothesis were true
What is sampling distribution?
the probability distribution of all values for an estimate that we might obtain when we sample a population
What is the standard error of an estimate?
the standard deviation of the estimates sampling distribution
The standard error of an estimate is an estimate of what?
the precision of the statistic in question
What can standard error be calculated for?
Precision, median, correlation, difference between means
What is variance
a measure of spread with useful mathematic properties
What is standard deviation?
commonly used measure of the spread that measures how far from the mean the observations typically are
What is standard deviation the square root of?
Variance
What is Akaike Information Criterion (AIC)?
a mathematical method for evaluating how well a model fits the data it was generated from
What is AIC used for?
comparing different models and determining which one is the best fit for the data
What is AIC calculated from?
The number of independent variables used to calculate the model-the maximum likelihood estimate of the model (how well the model reproduces the data)
What is the best fit model according to AIC?
the one that explains the greatest amount of variance using the fewest possible independent variables
What is the significance level?
a probability used as a criterion for rejecting the null hypothesis
What happens if your p-value is less than alpha?
reject the null hypothesis
What happens if your p-value is greater than alpha?
fail to reject the null hypothesis
What is type I error?
rejecting a true null hypothesis
What is type II error?
failing to reject a false null hypothesis
What is a test statistic?
a number calculated from the data that is used to evaluate how compatible the data are with the result expected under the null hypothesis
Is the p-value a test statistic?
No, the test statistic is compared to the null distribution in calculating a p-value
What is the null distribution?
The sampling distribution of outcomes for a test statistic under the assumption that the null distribution is true
How can we get different values under the null hypothesis in regards to the null distribution?
Sampling error
