Page Last Updated: May 22, 2026

Naming Conventions🔗

The instrument table and variable names used for tabulated HBCD study data largely follow standardized naming conventions adapted from the ABCD Study. This ensures consistency across instruments and derived datasets, allowing for intuitive parsing of variable meaning and structure.

Convention Logic & Rules🔗

The standard variable naming format is comprised of 4 or 5 main components separated by a single underscore ( _ ). The scale component is only present in a subset of instruments that contain multiple scales:

domain_source_table_{scale}_item

Variable names may also include subcomponents, separated by double ( __ ) underscores to indicate nested components of table, scale, and/or item. Subcomponents distinguish finer details such as subscales, versions, or counter types. Finally, multiselect fields are preceded by triple underscores ( ___ ), mainly relevant for Adult & Child Demographics table variables.

Example â–¸

Let's break down the following example: ncl_cg_spm2__inf_soc_001

  • ncl: Neurocognition & Language (domain)
  • cg: Caregiver (source)
  • spm2__inf: nested table name
    • spm2: the SPM-2 instrument (table)
    • inf: Infant version of SPM-2 (table subcomponent)
  • soc: scale for metrics of socialization (scale)
  • 001: item number (item)

Naming Component Definitions🔗

Details of individual naming components are as follows:

domain Data domain, e.g. bio (Biospecimens), img (Imaging) - see values key
source Can either be the subject/who the protocol element is about OR respondent/who completed the assessment. Examples include cg (Caregiver), ch (Child), etc. - see values key
table Instrument/protocol element name
{scale} Name of scale within instrument/protocol element for instruments with multiple scales (not including administrative/summary score variables). For example, the IBQ-R (VSF)+BI includes 4 scales, each indicated by a separate scale component (e.g. Behavioral Inhibition scale annotated by a value of beh in variable name mh_cg_ibqr_beh_001).
item Will either be an item number corresponding to individual questions in a scale (e.g. 001) or admin field/score label for administrative/summary score variables - see details
Values Key: domain & source â–¸
Domain ValuesDescription
bioBioSpecimens
mhBehavior/Child-Caregiver Interaction
eegTabular EEG
imgTabular Imaging
nclNeurocognition and Language
ntNovel Tech
pexPregnancy/Exposure Including Substance
phPhysical Health
sedSocial and Environmental Determinants
Source ValuesDescription
bmBiological Mother
cgCaregiver (Responsible Adult)
chChild
ldLinked Data
raRA (research assistant)
Administrative & Summary Score Variables â–¸

Administrative and summary score variable types include administrative fields and score labels in place of the item naming component, respectively. Possible values include:

Admin fields administration; location; lang; date_taken; candidate_age; gestational_age; adjusted_age
Score labels score; summary_score; total_score; etc.

Exceptions🔗

Some table/variable names deviate from the standard naming conventions. These exceptions are temporary and will be standardized in future releases. Main exceptions include:

  • Demographics domain tables (sed_basic_demographics and par_visit_data)
  • Biospecimen domain tables, e.g. bio_bm_biosample_nails_results
  • Administrative and summary score variables (e.g. date_taken, summary_score) often contain additional single underscores -see infobox for details

Tabulated Pipeline Derivatives🔗

Tabulated derivatives from imaging and EEG processing pipelines follow a standardized naming convention:

domain_pipeline_derivative
domain img (imaging) or eeg (EEG)
pipeline Name of the processing pipeline (e.g. xcpd)
derivative Basename of output files aggregated across participants

For example, the table name below corresponds to participant data aggregated across the XCP-D derivatives:

  • Table: img_xcpd_space-fsLR_seg_Gordon_stat-alff_bold.tsv
  • Derivatives: sub-[ID]_ses-[V0X]_task-rest_dir-PA_run-{X}_space-fsLR_seg_Gordon_stat-alff_bold.tsv