Table 1.

Inclusion and exclusion criteria, developed per the Population, Intervention, Comparison, Outcomes, and Study Design framework, for the scoping review.

Facet	Inclusion criteria	Exclusion criteria
Population	Any Twitter (Twitter, Inc) data on Twitter users, such as posts, profile details, photos, or avatars	Studies evaluating prediction from data on other social media platforms, such as Facebook (Meta Platforms, Inc) or Instagram (Meta Platforms, Inc)
Intervention	Methods for predicting the gender or age of Twitter users; articles that used machine learning, natural language processing, human in the loop, or other computationally assisted methods to predict the gender or age of the users	Studies that contained no computation methods
Comparator	Any or none; we included any studies irrespective of whether they had a comparator and, if they did have a comparator, irrespective of what that was	N/Aa
Outcome	Gender or age prediction	Any other demographic trait prediction
Study design	Any type of peer-reviewed study reporting on the methods used to predict gender or age; such information must be the primary focus of the study or reported in enough detail to be reproducible	Discussion papers, commentaries, and letters
Date	2017 or later	Before 2017
Language	All	None

^aN/A: not applicable.