20 terms

Statistics Test 2


Terms in this set (...)

Chi Square Assumptions
1. random sample
2. no expected frequencies less than 5 in any given cell
Meaning of a t-statistic
the number of standard errors from the mean
Meaning of a Z statistic
the number of standard errors from the mean
Why does sampling matter?
sampling matters to make results general in order to apply to the larger group
Non-Probability Sample
(bad) convenience sample, snowball sample, quota sample, judgment sample
Probability Samples
(good) simple random sample, systematic random sample, cluster sample, stratified random sample
Phrase for Standard Error
average distance of the sample statistic from the population parameter
Z Score for 90% Confidence Level
Z Score for 95% Confidence Level
Z Score for 99% Confidence Level
How to Calculate Confidence Interval
1. calculate standard error
2. calculate confidence interval
Phrase for Standard Deviation
the average distance from the mean
Central Limit Theorem
when N>30 or 50 the population curve will always be normal
Confidence Interval
a range of values defined by the confidence level within which the population parameter is estimated to fall
Point Estimate
a sample statistic used to estimate a population parameter
Type 1 Error
our first concern in a court of law, we do not want to convict an innocent person
Type 2 Error
secondary concern, letting guilty person go free, or saying there is no difference when there really is
Degrees of Freedom
the number of scores that are free to vary in calculating each statistic
Sampling Error
the difference between the sample estimate and the population parameter
Sample Bias
the thing you sample from does not represent the entire population