Gnosis is a customizable spaced repetition system designed to enhance memory retention through active recall. It allows users to set specific review intervals for note decks & tags, creating an optimal learning environment tailored to each specific topic.

This manual is written for Gnosis version 0.4.0, released on 2024-08-7.

1 Introduction

Gnosis (γνῶσις) is a spaced repetition system that enhances memory retention through active recall. It employs a Q&A format, where each note consists of a question, answer, and explanation. Notes are reviewed at optimally spaced intervals based on the user’s success or failure to recall the answer. Key benefits arise from writing out answers when reviewing notes, fostering deeper understanding and improved memory retention.

Gnosis algorithm is highly adjustable, allowing users to set specific values not just for note decks but for tags as well. Gnosis’ adjustability allows users to fine-tune settings not only for entire note collections but also for specific tagged topics, thereby creating a personalized learning environment for each topic. Read more on 5

Before continuing reading this manual, it’s recommended you try out gnosis-demo.

2 Adding notes

Creating notes for gnosis can be done interactively with:

M-x gnosis-add-note

Or from within gnosis-dashboard

When it comes to adding images, you can select images that are inside gnosis-images-dir. For adjusting image size, refer to Customization

3 Note Types

3.1 Cloze

A cloze note type is a format where you create sentences or paragraphs with “missing” words. A fill-in-the-blanks question.

You can create a cloze note type using M-x gnosis-add-note and selecting Cloze, the question should be formatted like this:

{c1:Cyproheptadine::drug name} is a(n) {c2:5-HT2} receptor antagonist used to treat {c2:serotonin syndrome}

You can also format clozes like Anki if you so prefer; e.g {{c1::Cyproheptadine::drug name}}

  • For each cX-tag there will be created a cloze type note, the above example creates 2 cloze type notes.

  • Each cX tag can have multiple clozes, but each cloze must be a UNIQUE word, or a unique combination of words, in given note.

    • If a cloze is repeated, such as in phrases with “acetyl” & acetylcholine, include whitespace in the cloze to denote a single word.

  • You can use the keyword :: to indicate a hint.

You can remove the guidance string by adjusting gnosis-cloze-guidance.

3.2 MC-Cloze (Under development)

MC-Cloze is disabled by default, to enable it add to your configuration:

(add-to-list 'gnosis-note-types "MC-Cloze")

A MC-Cloze (Multiple Choice Cloze) is a fill-in-the-blank note, but unlike cloze note type the user is prompted to select an option instead of typing an answer.

You can create multiple notes from one input, but each note can only have one cloze. The first option will always be the right answer (will be randomized in the database), separated by the rest of the answer by gnosis-mc-cloze-separator (default value is “&&”), and a note will be generated from each cloze.

Example:

The greatest text editor is Emacs&&Vim&&Helix

When customizing gnosis-mc-cloze=separator pay attention to not use values that would mess up with regex functions.

3.3 MCQ

A MCQ note type, as the name suggests, is a multiple choice question.

The stem field (question) is separated by the options (choices) via gnosis-mcq-separator, each option is separated by gnosis-mcq-option-separator.

You can remove the guidance string by adjusting gnosis-mcq-guidance.

3.4 Basic Type

Basic note type is a simple question/answer note, where the user first sees a “main” part, which is usually a question, and he is prompted to input the answer.

3.5 Double

Double note type, is essentially a note that generates 2 basic notes. The second one reverses question/answer.

Ideal for vocabulary acquisition notes.

3.6 y-or-n

y-or-n (yes or no) note type, user is presented with a question and prompted to enter character “y” or “n”.

When using the hidden function gnosis-add-note--y-or-n, note that the ANSWER must be either 121 (y) or 110 (n), as those correspond to the character values used to represent them.

4 Customization

4.1 Image size

Adjust image size using gnosis-image-height & gnosis-image-width

Example:

(setf gnosis-image-height 300
      gnosis-image-width 300)

4.2 Typos | String Comparison

You can adjust gnosis-string-difference, this is a threshold value for string comparison that determines the maximum acceptable Levenshtein distance between two strings, which identifies their similarity

Let’s illustrate with an example:

(setf gnosis-string-difference 1)

In this scenario, we set gnosis-string-difference to 1. This implies that two strings will be recognized as similar if they exhibit a difference of at most one character edit.

To demonstrate, ’example’ and ’examples’ will be recognized as similar, considering that the latter involves just one additional character."

5 Gnosis Algorithm

Each gnosis note has a gnosis score, which is a list of 3 values, (gnosis-plus gnosis-minus gnosis-synolon/total). Gnosis-synolon is what is used to determine the next interval upon a successful recall, gnosis-plus is added to gnosis-synolon upon a successful recall as well, gnosis-minus is subtracted from gnosis-synolon upon failing to recall a note’s answer.

Gnosis has 2 special events, one is anagnosis ανάγνωση and lethe λήθη.

5.1 Anagnosis Event

Anagnosis, which means comprehension & recognition of knowledge, is triggered when the consecutive successful or failed recalls are equal or greater to anagnosis value.

When anagnosis is triggered by consecutive successful recalls, epignosis value is added to gnosis-plus. Epignosis means accuracy of knowledge.

When anagnosis is triggered by consecutive failed recalls, agnoia value is added to gnosis-minus. Agnoia means lack of knowledge

You can set specific values for each deck and tag of the variables mentioned above by adjusting gnosis-custom-values.

5.2 Proto

The default initial interval is defined at gnosis-algorithm-proto, you can define a custom initial interval for each deck as well.

gnosis-algorithm-interval is a list of numbers, representing the first initial intervals for successful reviews. There is no limit on the length of the list.

Example:

(setq gnosis-algorithm-interval '(0 1 2 30))

Upon each successful note review, the algorithm will increment to the next interval value: 0 days (0), 1 day later (1), 2 days later (2), and 30 days later.

Upon failing to review a note without completing it’s proto successful reviews, it’s next review date will be on the same date.

6 Editing notes

  • Currently there are 2 ways for editing notes:
    • You can edit a note after review by pressing e
    • Open gnosis-dashboard with M-x gnosis-dashboard, find the note you want to edit and press e

7 Sync between devices

Gnosis uses git to maintain data integrity and facilitate synchronization across devices.

You will need to configure your remote manually.

Example:

cd ~/.emacs.d/gnosis # default location for gnosis
git init # After completing your first review session, a git repo should have been initialized automatically.
git remote add origin <remote_url>
git push --set-upstream origin master

You can interactively use gnosis-vc-push & gnosis-vc-pull. As the name suggests, they rely on vc to work properly.

Depending on your setup, vc might require an external package for the ssh passphrase dialog, such as x11-ssh-askpass.

To automatically push changes after a review session, add this to your configuration:

(setf gnosis-vc-auto-push t)
(gnosis-vc-pull) ;; Run vc-pull for gnosis on startup

8 Configuring Note Types

8.1 Adjust Current Types Entries

Each gnosis note type has an interactive function, named gnosis-add-note-TYPE. You can set default values for each entry by hard coding specific values to their keywords.

For example:

(defun gnosis-add-note-basic (deck)
  (gnosis-add-note--basic :deck deck
                          :question (gnosis-read-string-from-buffer "Question: " "")
                          :answer (read-string "Answer: ")
                          :hint (gnosis-hint-prompt gnosis-previous-note-hint)
                          :extra ""
                          :images nil
                          :tags (gnosis-prompt-tags--split gnosis-previous-note-tags)))

By evaluating the above code snippet, you won’t be prompted to enter anything for extra & images.

8.2 Creating Custom Note Types

Creating custom note types for gnosis is a fairly simple thing to do

  • First add your NEW-TYPE to gnosis-note-types
    (add-to-list 'gnosis-note-types "NEW-TYPE")
  • Create an interactive function

Each note type has a gnosis-add-note-TYPE that is used interactively & a “hidden function” gnosis-add-note--TYPE that handles all the logic. You can use one of the current gnosis-add-note--TYPE functions or create one of your own.

Refer to gnosis-add-note-basic & gnosis-add-note--basic for a simple example of how this is done, as well as gnosis-add-note-double.

8.3 Development

To make development and customization easier, gnosis comes with gnosis-test module, that should be used to create a custom database for testing.

To exit the testing environment, rerun M-x gnosis-test-start and then enter n (no) at the prompt “Start development env?”