The Go Game Space Training Module presents Go problems grouped by technique or objective. Technique topics include "push and cut", the "elbow lock" tesuji, the "rooster on one leg" tesuji or the "under the stones" tesuji. Objective topics include attacking, defending, living, or strategic goals.
This structure allows you to study thousands of situations covering specific aspects of the game under controlled circumstances.
Select a topic to see the problems for that topic. The "related collections" links will show problems related to the current problem; this could include alternative opponent responses, refuting mistakes or follow-up problems. Problems are shuffled and randomly oriented. Use the "Randomize" link to re-shuffle and re-orient the current problem set.
The topics are, except for the "By Level" section, intentionally not divided by difficulty level; in a real game there are also problems of various difficulty. Even if you cannot find the solution, it is good to be exposed to new motifs and you can look at the solution using the question mark control.
Solve problems from a topic repeatedly until you have internalized the principles behind that topic.