Spaced Repetition Timing

The mechanics of decay

Forgetting is not a failure of memory. It is a biological necessity. Information that is not accessed decays predictably over time. Ebbinghaus demonstrated this curve over a century ago. If you review data too soon, you waste mental effort. If you review too late, the connection has vanished. Our algorithm aims for the peak of that decay curve. It finds the moment just before a memory becomes inaccessible. This is the optimal window for reinforcement.

Adjusting to performance

Pip tracks your performance on every item. Correct answers extend the interval between reviews. Incorrect answers reset the schedule. We do not use fixed intervals. A static schedule ignores the complexity of the material. Some concepts stick immediately. Others require repeated exposure. By using a weighted algorithm, we prioritize what you struggle to retain. If you recall an item easily, the gap to the next review expands. If you falter, the gap contracts. This ensures that you spend your time where it matters most.

Minimizing cognitive overhead

Complexity in UI is a tax on your attention. We removed all extraneous feedback loops from the review screen. You see the item, you attempt the recall, and you grade your own accuracy. The system calculates the next interval based on your response. This process reduces the time spent managing your study list. Your role is to provide the data. Pip's role is to order that data for efficiency. The algorithm runs in the background. It does not require manual intervention or constant adjustment. This is intentional. You should spend your time studying, not organizing your study system.

Current limitations

There are instances where the algorithm may feel aggressive. If you are learning new material at a high volume, the number of daily reviews will increase. Some users find this load unsustainable. You can manually adjust the review limit in settings, but we advise caution. Reducing the limit causes a backlog. A backlog forces the system to compress intervals. This effectively ruins the spacing benefit. We are currently working on a way to smooth out these spikes in volume. Until then, consistent daily use remains the most effective strategy for managing the load. Do not let the backlog grow beyond what you can handle in one session.