Interleaving works

The interleave principle. Random-looking order is actually the most efficient review schedule: switching mechanisms forces retrieval practice (you must recall which pattern applies instead of riding momentum from the last item). Research on learning calls this interleaving; the exam calls it Tuesday.

Practical interleave habits:

• After every switch, re-read the response format. Answering an MCQ with an implementation (or vice versa) is a zero.
• Keep a mistake tally across the set by MECHANISM, not topic: "two removal-discipline errors" tells you what to drill; "two ArrayList errors" doesn't.
• Treat every challenge as graded by its own rubric: MCQ = letter
  • explanation; trace = exact output; implementation = all tests.

The checkpoint is the set's final: five mechanisms, no labels, no mercy — but every one is a pattern you have already banked.