Flashcards in Chap 6 Standard Errors Deck (11):
Central Limit Theorem
The fact that as a sample size increases, the sample distribution of the mean becomes increasingly normal, regardless of the shape of the distribution of the sample.
Degrees of Freedom
Roughly the minimum amount of data needed to calculate a statistic. More practically, it is a number or numbers, used to approximate the number of observations in the data set for the purpose of determining statistical significance.
Expected Value of the Mean
The value of the mean one would expect to get from a random sample selected from a population with a known mean.
i.e. if one knows the population has a mean of 5 on some variable, one would expect a random sample selected from the population will also have a mean of 5.
Statistics generated from sample data that are used to make inferences about the characteristics of the population the sample is alleged to represent.
Sampling Distribution of the Differences b/w the Means
The distribution of scores that would be generated if one were repeatedly draw two random samples of a given size from a 2 populations and calculate the difference b/w the sample means
Sampling Distribution of the Mean
The distribution of scores that would be generated if one were to repeatedly draw random samples of a given size from two population and calculate the mean for each sample drawn.
A theoretical distribution of any statistic that one would get by repeatedly drawing random samples of a given size from the population & calculating the statistic of interest for each sample.
The standard deviation of a sampling distribution.
A term indicating that a phenomenon observed in a sample( or samples) has meaningful implications for the population.
i.e. That the difference b/w a sample mean and a population mean is statistically significant or that a relationship observed b/w 2 variables in a sample is strong enough, relative to the standard error, to indicate a relationship b/w the 2 variables in the population from which the sample was selected.
The standard error of the mean estimated from the sample standard deviation.
i.e. when a population standard deviation is unknown