Chapter 20

Question 1

Multilevel models should be used to analyse data that have a _____________structure.

Answer 1

hierarchical

Question 2

If you are measuring depression after psychotherapy and your sample of patients will see different therapists within different clinics- how many levels are in this hierarchy?

Answer 2

This is a three-level hierarchy with:

1. depression scores from patients
2. nested within therapists
3. who are nested within clinics

Question 3

In ordinary regression, parameters generally are a ______ ______ estimated from the sample (a _____ ____)

Answer 3

In ordinary regression, parameters generally are a FIXED VALUE estimated from the sample (a FIXED EFFECT).

Question 4

Hierarchical models are just like regression, except that you can allow… (this is called a ________effect)

Answer 4

Hierarchical models are just like regression, except that you can allow PARAMETERS TO VARY (this is called a RANDOM effect)

Question 5

If we estimate a linear model within each context rather than a sample as a whole, then we can assume… or…

Answer 5

that the intercepts of these models vary OR that the slopes of these models differ

Question 6

If intercepts of a model vary we have a …

Answer 6

random intercepts model

Question 7

We can compare different multilevel models by looking at …

Answer 7

…the difference in the value of −2LL.

Question 8

Under what circumstances would we compete different models by looking at the difference in the value of -2LL?

Answer 8

when we have changed one parameter or added one new thing to a model

Question 9

For any model we have to assume a…

Answer 9

…covariance structure.