Exam 21: Multilevel Linear Models

In a multilevel model in which reaction times on different trials (level 1) were collected from within different people (level 2), what does the intraclass correlation represent?

The SPSS output below is from a multilevel model. What does UN(1,1) estimate?

Multilevel linear models differ from regression in that they:

The graph below is from Wright and London (2009). Which of the following descriptions best applies to this graph:

In a multilevel model in which an outcome was measured in children from different classrooms, a large intraclass correlation would imply that:

A researcher had data collected at several schools measuring children's emotional intelligence, age, and academic performance. Which analysis should they perform to test whether academic performance is predicted by emotional intelligence when controlling for age, taking into account that students were from different schools?

A paediatrician measured children's asthma and stress levels each month for six months. What analysis would they use to find out whether stress significantly predicts asthma?

What do we mean by centring?

What is a second-order polynomial also known as?

In the context of multilevel models what do we mean by a random regression coefficient?

It is common when fitting multilevel models to start with a simple model, and build it up by adding new terms and re-estimating the model. If you want to compare the fit of a multilevel model with a simpler variant of the same model, what estimation method must you use?

The matrix below describes what kind of covariance structure in a multilevel model? $\left( \begin{array} { l l l l } 1 & 0 & 0 & 0 \\0 & 1 & 0 & 0 \\0 & 0 & 1 & 0 \\0 & 0 & 0 & 1\end{array} \right)$

The matrix below describes what kind of covariance structure in a multilevel model? $\left( \begin{array} { c c c c } \sigma _ { 1 } ^ { 2 } & \sigma _ { 21 } & \sigma _ { 31 } & \sigma _ { 41 } \\\sigma _ { 21 } & \sigma _ { 2 } ^ { 2 } & \sigma _ { 32 } & \sigma _ { 42 } \\\sigma _ { 31 } & \sigma _ { 32 } & \sigma _ { 3 } ^ { 2 } & \sigma _ { 43 } \\\sigma _ { 41 } & \sigma _ { 42 } & \sigma _ { 43 } & \sigma _ { 4 } ^ { 2 }\end{array} \right)$

The matrix below describes what kind of covariance structure in a multilevel model? $\left( \begin{array} { c c c c } 1 & \rho & \rho ^ { 2 } & \rho ^ { 3 } \\\rho & 1 & \rho & \rho ^ { 2 } \\\rho ^ { 2 } & \rho & 1 & \rho \\\rho ^ { 3 } & \rho ^ { 2 } & \rho & 1\end{array} \right)$

In the context of multilevel models what do we mean by a fixed regression coefficient?

Which of the following is a measure of the fit of a multilevel model?

The SPSS output below is from a multilevel model. What does UN(2,1) estimate?

In the output for a multilevel model, the coefficient estimate for each effect can tell us:

The matrix below describes what kind of covariance structure in a multilevel model? $\left( \begin{array} { c c c c } \sigma _ { 1 } ^ { 2 } & 0 & 0 & 0 \\0 & \sigma _ { 2 } ^ { 2 } & 0 & 0 \\0 & 0 & \sigma _ { 3 } ^ { 2 } & 0 \\0 & 0 & 0 & \sigma _ { 4 } ^ { 2 }\end{array} \right)$

The SPSS output below is from a multilevel model. What does UN(2,2) estimate?