TABLE II.

Cryo-EM community data archiving and validation workshops.

#	Year	Title/location	Organizers	Description	Key outcomes
1	2002	IIMS Workshop, UK	Kim Henrick, José-María Carazo, Stephen Fuller	Promote software development in the field of 3DEM molecular structure determination	Guidelines and release policies for the new EMDB archive.10,11,39 Deposition system to collect EMDB data and maps9
2	2004	3DEM Developers workshop, UK	Kim Henrick	Developer review of tools and software practices used in the field of cryoEM	Priorities developed for EMDB including electron tomography, PDB-EMDB cross-referencing, lossless map conversion, review of community map standards and conventions
3	2004	Cryo-EM Structure Deposition Workshop, NJ, USA	Helen Berman, Wah Chiu, Michael Rossmann	Develop community consensus on data items needed for deposition of maps and atomic models derived from cryoEM	Need for deposition one-stop-shop articulated. Recommendations incorporated in extended EM data dictionary13
4	2005	3DEM Developers Workshop, UK	Kim Henrick	Introduced EM data dictionary to software developers to facilitate its integration into 3DEM packages and electronic notebooks	Agreement to adopt a common set of conventions for maps22
5	2006	CryoEM Standards Task Force, TX, USA	Wah Chiu, David Belnap, José-María Carazo	Gather cryoEM map conventions and formats with associated metadata used by different developers	Key conventions (e.g., Euler angles) were evaluated for interoperability and conversion tools were created40,41
6	2008	Electron Crystallography Data Model Workshop, CA, USA	Wah Chiu, Cathy Lawson	Gather expert advice on metadata items in the EM dictionary pertaining to electron crystallography	Recommendations incorporated into EM data dictionary13
7	2010	EM Validation Task Force, NJ, USA	Helen Berman, Wah Chiu, Gerard Kleywegt, Cathy Lawson	Expert review of potential validation standards for maps and models produced by 3DEM reconstruction	Recommendations summarized in white paper,25 and implemented in OneDep validation reports14,18
8	2011	Model Challenge Workshop, HI, USA	Steve Ludtke, Cathy Lawson, Gerard Kleywegt, Helen Berman, Wah Chiu	Computational groups described and compared tools they used to model a selected set of published cryoEM structures	Results published in Biopolymers journal special issue42
9	2011	Data Management Challenges in 3DEM, UK	Ardan Patwardhan, Gerard Kleywegt, Jason Swedlow	Gather expert advice on key topics in data archiving and validation for 3DEM data, including data model, validation, raw-data archiving	Recommendations summarized in white paper.23 Web-based visualization tools developed.28 EMPIAR raw data archive created.15 Extended data model implemented17
10	2012	3DEM Modeling Workshop, TX, USA	Wah Chiu	Current challenges in creating and validating coordinate models built into cryo-EM maps	Recommendations gathered for modeling and validation standards and future model challenges
11	2012	3D Cellular Context for the Macromolecular World, UK	Ardan Patwardhan, Gerard Kleywegt, Jason Swedlow	Discussions on data archiving and validation for emerging 3D cellular imaging techniques	Recommendations summarized in white paper24
12	2012	Instruct Image Processing Center Developer Workshop, Spain	José-María Carazo	Effort to standardize information exchange in single particle reconstruction and to establish algorithm benchmarking	CTF benchmarking challenge43 and EMX convention for CTF and single-particle parameters developed44
13	2015	CryoEM Model Validation Workshop, MA, USA	Wah Chiu, Cathy Lawson, Paul Adams	Modeling experts met to present and discuss challenges in modeling into cryoEM maps	Gathered recommendations5 directly used in development of 2016 Model Challenge
14	2015	Building Bridges between Cellular and Molecular Structural Biology, UK	Ardan Patwardhan, Gerard Kleywegt	Expert discussions on how to integrate structural data from a diverse range of public archives covering cellular and molecular structural biology	Recommendations to develop tools/file formats for map segmentation, and tools to support biological structure annotation described in white paper45
15	2017	Model Challenge Assessment, LA, USA	Wah Chiu, Cathy Lawson, Paul Adams	First pass analyses of models and data submitted to the 2016 Model Challenge	Recommended metrics implemented on model challenge comparison website46
16	2017	CryoEM Structure Joint Challenges Workshop, CA, USA	Cathy Lawson, Wah Chiu	Joint review of the 2016 Map and Model Challenge activities	Results described in Journal of Structural Biology special issue;30 also featured in Nature Methods editorial47
17	2019	Frontiers in cryo-EM Validation, UK	Gerard Kleywegt, Garib Murshudov, Elena Orlova, Ardan Patwhardhan, Alan Roseman, Peter Rosenthal, Maya Topf, Martyn Winn	Discuss current and future community needs/challenges for validation tools to support maps and models from single-particle analysis	Meeting featured in 2018 Nature editorial.48 Recommendations white paper is in preparation
18	2019	Model Metrics Workshop, CA, USA	Cathy Lawson, Wah Chiu	Review modeling processes and assessment results of the 2019 Model Metrics Challenge and plan for future events	Recommendations editorial and full event manuscript are in preparation