DOI: 10.5519/hay2d5yo
title: Join the Dots collection-level descriptions

description: The records in this dataset provide a high-level summary of the Natural History Museum's collection and encompass the material managed by its Life Sciences, Earth Sciences and Library & Archives departments. The data has been gathered, structured and published with the intention of providing some level of visibility into the scope, nature and composition of the Museum's holdings, the majority of which have yet to be digitised. The 2,800+ records in this dataset represent the majority of the NHM collection, approximately 78 million items, and should be treated as an index or discovery tool: they are an indicative view of the Museum's holdings, a source of high-level figures and a signpost towards the relevant curatorial team to contact for more in-depth information.
 
## Descriptive fields
 
Each record in the **JtD collection-level records** table describes a group of objects, referred to as a 'collection unit'. Collection units can range in size from a handful of objects to several million and are defined by a set of high-level characteristics common to the objects within them (e.g., taxonomy, straitgraphy, item type, preservation method). Controlled vocabularies and external authority lists underpin descriptive fields wherever possible: see **Data dictionary** for field-level definitions and guidance for all fields used in this dataset. 

## Collection metrics

The count fields indicate the scale of each collection unit in terms of the estimated quantity of 'items' (specimen-level or equivalent) and 'curatorial units' (objects physically managed during curation activities, such as jars or boxes) it holds. The 'reporting count' field should be used when aggregating multiple units and is the default collection size metric used by the Museum both internally and externally. 

Assessment scores are allocated by curatorial teams and are an attempt to indicate subjective or mutable qualities of each collection unit, such as outreach potential, scope and significance, physical accessibility and level of information available. See **Data dictionary** and **Join the Dots User Manual** for scoring definitions and examples. Scores are updated on an annual basis and are best viewed as a benchmark of the state of a collection unit/group of units: they are intended to allow us to track the impact of collection care, development and management activities over time and are not intended for use as a comparative measure between different areas of the collection. 

## Join the Dots Framework

The criteria underpinning collection units and the methodology by which they are quantified and assessed is defined in the Join the Dots (JtD) cross–disciplinary collection assessment framework, developed and used at the NHM since 2018. For details on the full JtD framework see **Join the Dots User Manual** and the summary paper referenced below. Note that not all fields referenced in the JtD specification are included in this dataset: a subset is presented to avoid compromising the security of the collection and to provide a level of detail relevant to an external audience.

## Further references 

- [NHM main website collection pages](https://www.nhm.ac.uk/our-science/collections.html)
- [Library & Archives Discovery Layer](https://www.nhm.ac.uk/our-science/departments-and-staff/library-and-archives.html)
- [Archives Catalogues](https://www.nhm.ac.uk/CalmView/default.aspx)
- [Specimen-level collection dataset](https://doi.org/10.5519/0002965)
- [Join the Dots: assessing a collection of 80 million items at The Natural History Museum, London, 2022](https://www.tandfonline.com/doi/full/10.1080/09647775.2021.2023900) - currently paywalled: contact the dataset curator for a copy