A computer-implemented method for computer-based testing via delivery of at least one computer-based test, the at least one computer based test having at least one computer-based test component, each computer-based test component having a delivery source and a delivery volume, the computer comprising a processor, the method comprising:
- storing via the processor the at least one computer-based test and delivering over an electronic data network said computer-based test to at least one test candidate by delivery storage means;
- controlling delivery of said computer-based test from said delivery storage means by test driver means via the processor;
- caching and storing said computer-based test in cache storage means in response to monitoring of at least one testing environment variable including a latency of the electronic data network;
- and
- adapting via the processor the delivery volume of the at least one computer based test component, based upon detecting a change in the at least one testing environment variable,
- wherein, when network communication failure is detected via the cached computer-based test, the at least one computer-based test can be taken by the at least one test candidate while connectivity to a redundant network is being established in the background.