IncRem Scheduler¶

This page explains how the plugin calculates the next review interval each time you press Next on an Incremental Rem, and how to choose which scheduler an item uses.

[!NOTE] "Interval" here means days until the next review after pressing Next. This is separate from the Initial Interval setting, which controls how many days pass between tagging a Rem as incremental and its first appearance in the queue (before any review happens).

Two schedulers¶

Incremental Rems cover a wide range of processing depth, and no single rule suits all of them:

Stage	Example	Typical reviews	What it needs
📕 Raw import	An entire PDF book	20–50+	To come back often enough to be finished
📄 First extract	A chapter or section	10–20	The same, on a smaller scale
📝 Refined extract	A paragraph	5–10	Growing gaps
💡 Atomic fact	A sentence you already know well	2–4	Long gaps you choose, kept from one review to the next

So the plugin has two schedulers, and every Incremental Rem uses one of them:

	Multiplier	Saturating Curve
Next interval comes from	The interval the item is on	The number of reviews
Growth	Unbounded: × the multiplier at every review	Levels off below a ceiling
An interval you set in Reschedule	Is kept and multiplied from then on	Is a one-off; the curve resumes afterwards
Suits	Extracts, paragraphs, sentences	Books, chapters, long videos

Multiplier scheduler¶

next interval = ⌈ current interval × multiplier ⌉  days

The current interval is the one the item was last put on, whoever chose it: the previous Next, a Reschedule (in the queue or the editor), the Priority & Interval popup shown when the Rem was created, or a manual edit of the Next Rep Date. The multiplier defaults to the Multiplier setting (1.5) and can be changed for a single Rem.

That is the point of this scheduler: an interval you choose is remembered. Take a sentence you extracted from a book and know well, but must not forget. You give it 50 days when you create it. In 50 days you read it again and press Next:

Review	Multiplier 1.5
Created with	50 d
1st Next	75 d
2nd Next	113 d
3rd Next	170 d

Left alone from the default 1-day Initial Interval, the same multiplier gives 2 → 3 → 5 → 8 → 12 → 18 days.

Details worth knowing

It uses the scheduled interval, not the time that actually passed. Reviewing an item late, because the queue was overloaded, does not inflate its interval.
A multiplier of 1 keeps the interval constant — "show me this every 50 days". The allowed range is 1 to 10.
A multiplier above 1 always moves the interval by at least a day, and an interval of 0 counts as 1, so an item never gets stuck.
Swiping Next to "tomorrow" or "today" does not change the interval. Those gestures mean "carry on soon", so the next Next still multiplies the interval the item had before the swipe.

Replaces the old exponential scheduler

Before v1.0.148 the default scheduler was ⌈Multiplier ^ N⌉, where N is the number of reviews. For an item you never reschedule the two give almost the same sequence. The difference is what happens after you choose an interval yourself: the old formula ignored it at the next review, the multiplier scheduler builds on it.

Saturating Curve scheduler¶

The saturating curve ignores the interval the item is on and looks only at how many times you have reviewed it. It:

Starts at a comfortable interval you choose (default 5 days).
Gradually approaches a ceiling you set (default 30 days), growing slower the closer it gets.
Never exceeds the ceiling, so high-volume items are always revisited in time.

Formula¶

interval = ⌈ firstReviewInterval + (maxInterval − firstReviewInterval) × (N−1) / (N−1+4) ⌉

N is the review number. The constant 4 controls how quickly the curve saturates: by review 5 you're halfway between your first-review interval and the max.

Example progression (First Review Interval = 5, Max Interval = 30)¶

Review	Fraction	Interval
1st	0 %	5 d
2nd	20 %	10 d
3rd	33 %	14 d
4th	43 %	16 d
5th	50 %	18 d
6th	56 %	19 d
8th	64 %	21 d
10th	69 %	23 d
15th	78 %	25 d
20th	83 %	26 d

Because it depends only on the count, a Reschedule on a curve item is a one-time postponement: the next Next returns to the curve. That is what you want for a book you push a month ahead while you read its prerequisites.

Which scheduler an item uses¶

Three layers decide, the most specific one winning:

The Rem's own choice, set in the Reschedule or Priority & Interval popup.
The setting for its type, if you set one.
The Default Scheduler setting.

Per-type defaults¶

Each kind of Incremental Rem can have its own scheduler and its own Initial Interval:

Type	Applies to
Documents (PDF / web page)	A Rem that opens a whole PDF or web page, including a Rem that has one as its source
Videos	A Rem that opens a whole video
Highlights and Video Extracts	A PDF or web page highlight that is itself an Incremental Rem (the toolbar toggle), and video extracts
Regular Rems	Everything else: a paragraph, a sentence, a note

Scheduler for … starts at Use the Default Scheduler.
Initial Interval for … starts empty, which means "use the general Initial Interval". Type a number of days to give that type its own; 0 means due today. It is what a new Rem of that type is scheduled with, and what the Priority & Interval popup suggests.

The Initial Interval matters most on the Multiplier scheduler, where it is the interval the following ones grow from: 10 days with a multiplier of 1.5 gives 10, 15, 23… On the Saturating Curve it only places the first repetition.

A Rem created from a highlight is a regular Rem

The highlight toolbar's Create Incremental Rem button makes a new, ordinary Rem holding the highlight's text. It follows the Regular Rems settings, not the Highlights ones.

A common setup: Default Scheduler = Saturating Curve for the raw material, Scheduler for Regular Rems = Multiplier for what you extract from it.

Changing it for one Rem¶

The Reschedule popup (Ctrl+J) and the Priority & Interval popup both have a Scheduler row:

← / → switch between × Multiplier and Saturating Curve.
With the multiplier selected, ↑ / ↓ step its value by 0.1, or type a number.
A line underneath previews what follows the interval you are setting, e.g. After that: 75 → 113 → 170 days, and another says whether the Rem now differs from the settings.

The Reschedule popup with its Scheduler row: × Multiplier selected, the multiplier at 1.5 and the preview "After that: 36 → 54 → 81 days"

Above: the Reschedule popup (top) and the Priority & Interval popup shown when a Rem is made Incremental. Both report "Same as the setting for this type", so nothing is stored on the Rem.

The choice is saved with the popup. A Rem only stores it when it differs from what the settings give it; choosing the same thing again clears it, and the Rem goes back to following the settings as you change them.

Seeing which one is in use¶

Next button — a small chip before the interval: ×1.5 for the multiplier, curve for the saturating curve. The chip is outlined when the scheduler was chosen for that Rem. Hover it for the details.

Repetition History popup — the line under the totals names the scheduler and where the choice comes from: set for this Rem, type setting or default.

The Repetition History popup; the line under the totals reads "Scheduler: Multiplier ×1.5 (type setting)"

Settings Reference¶

All of these are in the Scheduling group of the settings popup.

The Scheduling group of the settings popup: Initial Interval and its four per-type settings, Default Scheduler, Multiplier, the two Saturating Curve settings and the four per-type schedulers

Above: an example setup — whole documents on the Saturating Curve, highlights and regular Rems on the Multiplier with a 10-day Initial Interval.

Setting	Type	Default	Description
Initial Interval	Number	`1`	Days before a new IncRem first appears in the queue (before any review), on either scheduler. On the Multiplier scheduler it is also the interval the following ones grow from.
Initial Interval for Documents / Videos / Highlights and Video Extracts / Regular Rems	Text	(empty)	Per-type Initial Interval in days. Empty = use the general one.
Default Scheduler	Multiplier / Saturating Curve	`Multiplier`	The scheduler used when neither the Rem nor its type says otherwise.
Multiplier	Number	`1.5`	Multiplier scheduler: `next interval = current interval × multiplier`. The value suggested for every Rem; `1` keeps the interval constant.
First Review Interval (Saturating Curve)	Number	`5`	Saturating Curve: interval in days after the first review.
Max Interval (Saturating Curve)	Number	`30`	Saturating Curve: ceiling the interval gradually approaches but never exceeds.
Scheduler for Documents / Videos / Highlights and Video Extracts / Regular Rems	Dropdown	`Use the Default Scheduler`	Per-type defaults that prevail over the Default Scheduler.

How this compares to SuperMemo's A-Factors¶

SuperMemo brings in its documentation:

The algorithm for determining inter-review intervals for topics is much simpler and is entirely under your control. Each article receives a specific priority. The priority determines which articles are reviewed first and which can be postponed in case you run out of time. Each article is also assigned a number called the A-Factor that determines how much intervals increase between subsequent reviews. For example, if A-Factor is 2, review intervals will double with each review. Priority and A-Factors are set automatically, but you can change them manually at any time. Priorities and A-Factors are determined and modified heuristically on the basis of the length of the text, the way it is processed, the way it is postponed or advanced, and by many other factors.

The multiplier scheduler is the same idea: a per-item factor applied to the item's current interval. What the plugin does not copy is the automatic part. A multiplier is never adjusted behind your back from text length or postponements; it is the Multiplier setting until you change it for a Rem.

The reason for having it is convenience, not memory science. Spacing improves retention, but the theory of an optimum interval applies to active recall (flashcards). For passive reading there is no such thing as an optimum interval, so the goal is simply a scheduler that keeps the intervals you want with the least effort: one that remembers a long interval you chose for a sentence, and another that keeps a book coming back.

Scheduling and the Queue¶

The scheduler described above determines when an Incremental Rem becomes due again. But once an item is due, how does the queue decide which item to show you first?

Due Date is a Yes/No Gate¶

The due date is not a ranking factor. The queue does not care about how overdue an item is — whether it was due 1 hour ago or 3 months ago makes no difference. The due date serves purely as a binary filter:

Due (Date.now() >= nextRepDate) → the item enters the pool of candidates.
Not due → the item is excluded entirely.

An item that has been overdue for months receives no special treatment over an item that became due just now. This is by design: in the context of passive reading material, there is no meaningful "urgency" metric tied to overdue time the way there is for flashcards.

Priority is the Sole Sorting Criterion¶

Among all items that pass the due-date filter, the queue sorts them strictly by Priority (lower number = higher priority). A Priority 5 item will always appear before a Priority 30 item, regardless of how long either has been waiting.

Controlled Randomness¶

After sorting by priority, the Sorting Randomness setting introduces a configurable degree of shuffling:

0% randomness: The queue is fully deterministic — always the highest-priority due item first.
20% randomness (default) and above: A slice of the sorted list is randomized via a priority-weighted lottery — lower-priority items get a chance to surface, but the items pulled forward are drawn in proportion to their priority weight (not uniformly). This prevents the queue from becoming too rigid while keeping the priority gradient intact, so higher settings stay safe. (Note: the slider is non-linear and eases in, so the left portion finely tunes small amounts while the middle reaches a meaningful ~25%.)