# Make a collection

> Tell Clusters which books, notes or Base rows to read, and through which lens.

A collection is one note in the collections folder (`Clusters` by default), named for the collection. Its properties say where its documents come from and which lens reads them.

## Make one from settings

1. Open **Settings → Clusters → Collections** and select **New collection…**.
2. Enter a **Name**, choose a **Source** and a **Lens**, and optionally a line under **About** saying what the collection is about.
3. Select **Create**. The note opens; you can read and edit it.

![The New collection dialog](img/2-new-collection.png)

| Source | What you enter | What becomes a document |
|---|---|---|
| **Notes in a folder** | The folder's path, such as `Research/Reading` | Every note in the folder and its subfolders |
| **Notes with a tag** | The tag, without `#` | Every note with that tag |
| **Rows of a Base** | The Base file, such as `Lists/Reading.base` | The note behind each row of a view |
| **Books on a shelf** | The shelf's name | Every book on that Books & Shelves shelf |

## The collection note

You can also write the note by hand. Its properties:

```yaml
reader: nonfiction              # the lens: a built-in one, or one of yours
source: folder Research         # books · shelf <name> · folder <path> · tag <tag> · base <file.base>#<view>
context: Notes from field work. # optional: what the collection is about
```

The property for the lens is named `reader`. A Base source may name a view after `#`; without one, its first view is used.

## How documents are split into passages

- **Notes** are one passage each. A note longer than the lens's limit is split at its `##` headings. A note's properties become its fields, which you can filter by in search.
- **A Base** is read through Obsidian: the view's filters and formulas decide the rows, and each row's columns are its fields. This needs the Bases core plugin.
- **Books** are split at their contents entries, or at their own headings. When a book's contents are thin, or the book is a PDF, a model finds where each part begins; Clusters asks before it makes that call.

Clusters never reads its own folders as a source.

## Preview before you index

Run **Clusters: Preview a collection's passages** to see each document's passages, and anything left out and why. It writes nothing.

## See your collections

The **Collections** tab lists each collection with its source and lens, and whether its index is **Up to date** (an index run would do nothing), what a run would still do ("153 passages to read"), or **Not indexed yet**. Its counts line gives the cards, the topics and how much the index takes on disk. Select one to open its dialog: **Index…**, **Keep up to date**, **Find topics…**, **Survey…**, then **Search…** and **Draft…**, its recent runs and **Open note**. The tab's **Recent activity** has **Undo a run…** and **Open jobs**.

![The Collections tab: one collection's row with its source, lens, counts and state, then Recent activity](img/3-collections.png)

![A collection's dialog: Index, topics, fields, Keep up to date, Search and Draft, its runs](img/4-collection-dialog.png)

## Related

- [Index a collection](index-a-collection.md)
- [Choose or make a lens](lenses.md)