The phrase "formal classes" refers to the structured and organized lessons that are taught in a traditional educational setting, such as a school or university. Full definition
The first formal class in shelter medicine did not take place until 1999. (outthefrontdoor.com)
Just becoming familiar with social networking sites, however, doesn't mean that teachers will be able to directly use them as a tool for formal class discussion or collaboration. (gse.harvard.edu)
In lieu of formal classes, students engage in weekly group critiques and reading groups, discussing art theory, criticism, and philosophy. (carrollcountytimes.com)