Understanding power and rules of thumb for determining sample sizes
... 4. Plot the given statistic by frequency of value. For instance, the following steps could be used to create a sampling distribution for the independent samples t‐test (based on Fisher 1925/1990; Pearson, 1990). 1. Select two samples of a given size from a single population. ...
... 4. Plot the given statistic by frequency of value. For instance, the following steps could be used to create a sampling distribution for the independent samples t‐test (based on Fisher 1925/1990; Pearson, 1990). 1. Select two samples of a given size from a single population. ...
Confidence regions and tests for a change
... where a, b and c are known functions which specify the distribution, and (f>{ is a known dispersion parameter. If Xt is discrete, then j{xt) is the probability function rather than the density. This general model covers many important cases. For this example, where we assume that the intervals betwe ...
... where a, b and c are known functions which specify the distribution, and (f>{ is a known dispersion parameter. If Xt is discrete, then j{xt) is the probability function rather than the density. This general model covers many important cases. For this example, where we assume that the intervals betwe ...
sample
... if the average meets national standards. Compare vitamin content of bread immediately after baking versus 3 days later (same loaves are used on day one and 3 days later) Compare vitamin content of bread immediately after baking versus loaves that have been on shelf ...
... if the average meets national standards. Compare vitamin content of bread immediately after baking versus 3 days later (same loaves are used on day one and 3 days later) Compare vitamin content of bread immediately after baking versus loaves that have been on shelf ...
Document
... the maximum error of estimate for the mean density. The steps to calculate the maximum error of estimate are: Find the sample statistics n and x . Specify if known. Otherwise, if n30, find the sample standard deviation, s, and use this as an estimate of . Find the level of z that corresponds to ...
... the maximum error of estimate for the mean density. The steps to calculate the maximum error of estimate are: Find the sample statistics n and x . Specify if known. Otherwise, if n30, find the sample standard deviation, s, and use this as an estimate of . Find the level of z that corresponds to ...
What if you want to test different variables within one experiment
... Assumption of sphericity: Variances of the differences between treatment levels are equal. This is often not the case in repeated-measures experiments. E.g. if you compare vowel durations for 10 speakers with normal and fast speech rate, then you are likely to get different variations for the two se ...
... Assumption of sphericity: Variances of the differences between treatment levels are equal. This is often not the case in repeated-measures experiments. E.g. if you compare vowel durations for 10 speakers with normal and fast speech rate, then you are likely to get different variations for the two se ...