Term
What is standard deviation? |
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Definition
How much the scores deviate from the mean |
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Term
What is an extreme score? |
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Definition
It is a score that is more than 2 std deviations away from the mean. |
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Term
What are the chances of extreme scores in a data sets with a normal distribution?
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Definition
Extreme scores with more than 2 standard deviation from the mean will occur only 5% of the time. |
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Term
How does 5% of extreme score principle apply to a normal distributed bell shape curve? |
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Definition
There is a 2.5% chance of extreme scores occuring on each tail/end of the curve. |
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Term
What is the general possibility of inference error (false alarm error rate/alpha level) allowed in Psychology? |
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Definition
Alpha criterion is .05. We give ourselves the 5% chance that we may have made a wrong inference from that data analysis. (eg. 5% Falsely rejecting the Null Hypothesis) |
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Term
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Definition
It is an analysis of variance which compares the variation within groups to the variation between groups. |
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Term
How does the null hypothesis relate to ANOVA and a hypothetical Psychology experiment? How does this relate to p < .05? |
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Definition
Null Hypo is that the experiment had no effect, and that the differences/effect are due to chance to alone.
Thus p < .05 means that if null hypo is true, there is a less than 5% chance of observing differences due to chance found between samples. Hence null hypothesis is rejected.
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Term
What is the F statistics? How does it relate to signficance testing for differences not due to chance alone? |
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Definition
The F stat is a ratio of the variance of between group to variance of within groups. If a F stat is significantly large with a P < .05, there is significant difference not due to chance alone. |
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Term
What is SS-Within? What is SS-Between? What is formula for calulating F- stat? |
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Definition
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Term
What are other tests are required after a significant difference from the one way anova? |
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Definition
T-test= to determine where the difference between 2 group lies.
Bonferroni test= to do multiple comparisons to see where the differences lies and by how much. (For comparision of more than 2 groups)
Bonferroni also adjust p value to ensure there is a minimised chance of making wrong inferences which may occur in multiple comparisons. |
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