Behavioral Statistics 7
If sampling distributions of the mean/variance are calculated using n-1, they are.....?
Unbiased estimator
What are the three characteristics of a sample mean?
Unbiased estimator Follows central limit theorem Minumum variance
What can be computed to locate sample means for sampling distribution?
Z transformation
What does 10 to the 6th power equal?
1 million
What does a sampling distribution of all sample means or variances mean?
A distribution of all the sample means or sample variances that could be obtained in samples of a given size from the same population
What is a sampling distribution?
A distribution of the mean and variance for all possible samples of a given size from a population
How is the total number of samples possible calculated?
By taking the size of the population raised to the degree of the sample size: N^n
What explains the sampling distribution of possible sampling is approximately normally distributed regardless of the shape of the distribution in pop.?
Central limit theorem
What is typically conducted using a sampling strategy in which the same participant CAN NEVER BE SELECTED TWICE IN SAME SAMPLE?
Experimental research
What is most often applied by researchers and behavioral sciences?
Experimental sampling
True or False: Sample mean is always equal to pop.mean
False
True or False: Researchers typically do sample with replacement while the development of statistical theory was based on use of sampling with replacement
False; they do not sample with replacement
What is the one disadvantage of dividing SS by df to obtain an estimate of pop. variance?
It does not have minimum variance
What is the formula for computing a possible number of samples that can be used in research?
N!/n!(N-n)!
True or False: A sampling distribution is not a distribution of scores in a population
True
True or False: As SS increases, standard error of meandecreases
True
To say that the sample mean is an unbiased estimator of the population means is a way of saying if we select a sample at random, then....?
On average we can expect the sample mean to equal the pop. mean
What is a distribution of all sample means for sample variances that could be obtained in samples of a given size from the same population?
Sampling distribution
What are the values along the x-axis for sampling means?
Sampling means (and the same holds for sample variances)
What is the standard error of the mean also known as?
Standard deviation in the sampling distribution of sample means
What was developed using a sampling strategy which the order of selecting participants matter the same participant could be selected twice in the same sample and participants are replaced after being sampled?
Statistical theory
How is SEM reported in text? Table? Graph?
Text: M= .... SEM=.... Table: (M+-SEM=....) Graph:Vertical bar extending above or below each mean plot
The mean in sampling distribution is equal to?
The population mean
If a researcher randomly selects a sample of participants and reports of their average score is a certain number, it means we can expect the pop. mean to equal the same number because.....?
The sample mean is an unbiased estimator of the pop. mean
What is the difference between experimental sampling and theoretical sampling?
experimental- the order of selecting individuals does not matter and each one selected is not replaced before selecting again theoretical- the order of selecting matters and each individual is replaced before sampling again
What is the difference between the shape of a sampling distribution of the mean vs. sampling distribution of the variances?
mean: approximately normal variances: approximately positively skewed
When is the sample variance an unbiased estimator of the pop. variance?
When dividing SS/ df or n-1