Education | EpiToDate

Self assessment
Case Study Scenarios
Practice with Dat

Self assessment

The self-assessment section, along with targeted quizzes across the site, provides an interactive way for you to test and deepen your understanding of core epidemiology concepts and reinforce critical principles.

Latent class analysis

Test your knowledge of the principles of latent class analysis

1 / 10

When conducting Latent Class Analysis, how can local dependence between observed variables within a latent class be addressed?

By using a hierarchical LCA model or introducing covariates

By increasing the number of latent classes

By assuming the observed variables are independent across classes

By removing any variables that exhibit dependence

2 / 10

What is one advantage of using Latent Class Analysis over traditional clustering methods like k-means clustering?

LCA can be used for continuous latent variables

LCA can handle categorical observed variables and provides probability-based class membership

LCA requires fewer parameters, making it simpler to implement

LCA automatically determines the number of classes based on data without needing model selection

3 / 10

In the context of LCA, what does entropy measure?

The degree of overlap between latent classes

The quality of classification, indicating how well individuals are assigned to latent classes

The accuracy of parameter estimates for observed variables

The overall fit of the model to the data

4 / 10

Which criterion is most often preferred for deciding on the number of classes in LCA models, especially when sample size is large?

Akaike Information Criterion (AIC)

Consistent Akaike Information Criterion (CAIC)

Bayesian Information Criterion (BIC)

Entropy

5 / 10

In Latent Class Analysis, what does the conditional independence assumption imply?

Each observed variable is assumed to be independent of all other observed variables, regardless of class membership.

The observed variables are conditionally independent given the latent class membership.

The latent classes are independent of each other given the observed variables.

Observed variables have no influence on latent class membership.

6 / 10

Which of the following is an indicator that you may need more latent classes in your model?

High Bayesian Information Criterion (BIC) value

Low entropy score

Large p-values for chi-square goodness-of-fit tests

Low Akaike Information Criterion (AIC) value

7 / 10

How would you interpret a situation in which adding covariates to an LCA model changes the distribution of individuals across classes?

The covariates improve the model’s fit by altering the latent class structure.

The covariates likely explain variance in class membership but do not impact the class structure itself.

The addition of covariates has caused overfitting in the model.

The observed variables are not conditionally independent within each class.

8 / 10

If an LCA model with three classes has a BIC of 2500 and an LCA model with four classes has a BIC of 2490, what does this suggest?

The four-class model should be chosen because it has a slightly lower BIC.

The three-class model should be chosen because it has fewer parameters.

The four-class model is invalid because the BIC should increase with additional classes.

The difference in BIC is too small to justify adding a fourth class.

9 / 10

If the entropy of an LCA model is low, what might this indicate about the model’s classification accuracy?

The model has high classification accuracy with distinct class boundaries.

The model’s classes are poorly defined, leading to lower confidence in class assignments.

The model has too many observed variables.

The model should include more latent classes to improve classification.

10 / 10

Which of the following would indicate that adding another latent class to an LCA model does not improve model fit?

An increase in the likelihood ratio

A decrease in the entropy of class membership

A minimal reduction in BIC or AIC compared to previous models

A significant increase in posterior probabilities

Your score is

The average score is 40%

Case Study Scenarios

The following are real-life epidemiology case scenarios where you can make decisions at each stage of an investigation (e.g., identifying study designs, selecting data collection methods, interpreting results).

Practice with Data

Latent class analysis

https://stats.oarc.ucla.edu/sas/dae/latent-class-analysis/
https://www.latentclassanalysis.com/code-repository/

Self assessment

Case Study Scenarios

Practice with Data

Share this: