Directionality

A Link is not just a connection; it has a direction. You always draw it from one note to another, so every link has a source and a target. Most of the time you can ignore this. When you can’t, directionality is the reason.

A → B is not B → A

“Spaced repetition” pointing to “Memory” says one thing: this note draws on, or leads to, that one. “Memory” pointing back to “Spaced repetition” says something else: this note is supported by, or exemplified by, that one. Same two notes, opposite arrows, different meaning. The direction is part of what the link says.

Out-links and in-links

Direction splits a note’s connections into two kinds:

• Out-links (what this note points to): the notes you reached for while writing this one. They show what it builds on.
• In-links, or backlinks (what points to this note): the notes that later reached back to it. They show what it supports.

This is the same split as in-degree and out-degree in Network Measures: a note many others point to is a key reference; a note that points to many is an index or an overview.

Backlinks travel both ways; direction still matters

Good tools make a directed link navigable from both ends: link A to B, and B gains a backlink to A. That two-way navigation is convenient, but it doesn’t erase the direction. The backlink still records who referenced whom, and that asymmetry is information. A note ten others point to is load-bearing in a way it isn’t if it’s the one pointing at ten.

Direction is where the meaning lives

Directionality matters most once you start naming your links (see Link). A named relationship usually only makes sense one way:

• depends-on: A depends on B, not the reverse.
• extends: A extends B.
• contradicts: A contradicts B.
• exemplifies: A is an example of B.

Reverse the arrow and you reverse the claim. A network of directed, named links can be walked like reasoning: follow the depends-on arrows and you trace an argument from its foundations upward.

Seeing direction

You don’t have to track any of this by hand. This site draws it for you: the per-page Connections graph and the NetworkMap render links as arrows. Outgoing links point away from a note, incoming links point toward it, and a link that runs both ways gets a head on each end.

Don’t overthink it

Directionality is a lens, not a chore. Capture a note, draw a link, and the direction comes for free: you drew it from here to there. Reach for it deliberately only when you’re building something that is a sequence, a dependency chain, an argument, a path of reasoning. The rest of the time, just link.