Term
How do independent measures and correlated groups t test differ? |
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Definition
Independent Measures: - 2 separate samples - presumed to come from 2 separate populations
Correlated Groups - single sample from single population used twice on the same dependent variable - 2 samples from same population |
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Term
Provide examples for a correlated groups t test. |
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Definition
- Before vs. After - Cond. 1 vs. Cond. 2, - Score at Time 1 vs. Score at Time 2 |
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Term
What advantages are there to running a correlated groups t test? |
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Definition
- more variables ascertained and controlled - more realistic design than 1 sample t and z - don’t need parameters like μ and σ - SS can be own control group (in repeated measures) |
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Term
What is the difference between repeated measures and matched pairs design? |
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Definition
repeated measures: - single sample randomly selected and generates 2 sets of data - don't need a control group because the sample is own control
matched pairs: - 2 heavily matched samples taken from single population and measured one time - matched on as many variables as possible |
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Term
What are the mechanics of a correlated groups t test? |
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Definition
- collect 2 sets of data in Correlated Groups t test - but use only 1 set of data called Difference Scores (D) --> all calculations use sample Difference scores in Correlated Groups t test. - makes this a 2 sample t test that looks like a 1 sample t test |
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Term
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Definition
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Term
What is represented by the denominator of this hypothesis test? |
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Definition
Smd (standard error of sample means) = estimated standard error for the Difference scores.It is how much we can expect between MD and μD to differ based on chance alone |
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Term
The sampling distribution for a correlated groups t test is what? |
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Definition
all the possible values of differences you can get between 2 scores on the x axis and the probability of getting those scores (y axis |
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Term
Denominator of an independent measures t test is... |
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Definition
sM = estimated standard error of the mean (estimated σM) where σ is unknown and we have to rely on the sample s to know how much difference we can expect between M and μ based on chance alone |
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