About mxlabs
A platform for practising econometrics: coding problems in R and randomised quiz questions.
What is mxlabs?
mxlabs has two banks of practice material. Coding problems, 167 of them, are written in R and solved in the browser. Quiz questions are multiple choice, generated fresh for each student so the numbers differ every time.
Topics range from sorting and cleaning data to causal inference. Both banks are free to practise, and both grow over time.
Tutors can assign either to a class and track completion. See Create Class Materials.
How it works
Problems are written in R, with pre-packaged functions limited to keep the focus on core principles. To calculate a mean, for example, you need to know the dataset dimensions and how to sum its columns.
Problems are tagged by difficulty and topic. Filter, run your code to check it works, then submit. After every solve you see how your solution compared with others.
Quizzes
Tutors create quizzes from the question bank and share a link with their class. Each student gets a version with randomised parameters: same question structure, different numbers. Students sign in with a one-click email link, submit their answers, and see results once the tutor releases them.
Assigning a quiz to a class needs tutor access, which we review and approve by hand. See Create Class Materials. Practising individual questions needs nothing: the Quiz Questions bank is open to anyone.
AI feedback
Request AI feedback on any attempt. It explains errors, identifies where logic broke down in wrong answers, or suggests improvements on correct ones.
Three free calls per day. Provide your email so we can track usage. See the Privacy & AI page for details.
Why mxlabs?
mxlabs addresses three gaps.
There is little opportunity to practise analytical coding in a way that builds methodological understanding. Pre-packaged functions exist for almost everything. Useful, but it can stop you learning the method underneath, universities included.
AI coding is making this worse. The productivity gains are real, but the wrong method, or the right method applied incorrectly, still drives the decision.
Assessing analytical skills is hard without seeing them in practice. Knowing your gaps and how you compare is useful to analysts, and to teachers and hiring managers.