We are receiving a lot of questions about relevant analyses in the Analyse-it Method Validation edition to help in evaluating new diagnostic tests in the fight against COVID-19. Below are some quick links that will help, but contact us if you have questions - we are working as normal.
Also see our latest blog post: Sensitivity/Specificity and The Importance of Predictive Values for a COVID-19 test
A scree plot visualizes the dimensionality of the data.
The scree plot shows the cumulative variance explained by each principal component. You can make decision on the number of components to keep to adequately describe a dataset using ad-hoc rules such as components with a variance > 0.7 or where the cumulative proportion of variation is > 80% or > 90% (Jolliffe 2002)