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RMA 3
LECTURE 3
Question | Answer |
---|---|
What is the importance of individual differences in psychological test data? | They make up variability in the data |
Why is there always variability in data? | All individuals are different |
What is systematic variability? | A consistent trend in data across all individuals |
What is the meaning of variance (s^2) in data? | It represents the average degree to which people differ from each other, and thus is a measure of variability. |
What is the meaning of standard deviation (SD)? | It reflects variability in terms of the size of raw deviation scores. |
What is the size of variance dependent on? | 1.The degree to which the scores in a distribution differ from each other 2. The metric of the scores in the distribution (e.g. scale of the test) |
How is co-variance computed? | It is coomputed from variability among scores in two different distributons of scores. |
What are the two pieces of information given by correlation scores? | The direction of the association, and the magnitude of the association. |
What are the three tpes of reliability? | Test-retest reliability, inter-rater reliability, internal consistency reliability |
How is Cronbach's alpha computed? | 1. Scores for each item obtained 2. Obtain the variance and covariance between the items 3. Sum the covariances among all pairs of items |
What does internal consistency reliability AKA Cronbach's alpha show? | Sum of covariances reflects degree to which responses to all items are consistent with each other. The larger this sum, the more consistent the items are. |