Database of Cross-Linguistic Norms, Ratings, and Relations for Words and Concepts as CLDF dataset -

Variable ENGLISH_DUNNO

This is the proportion of valid responses that are a rating and not a 'don't know'.

Value	Word	Concept

Language:	English
Category:	ratings
Result:	familiarity
Method:	users
Type:	percentage (float)

Dataset

Kuperman 2012 AoA

This list includes age-of-acquisition (AoA) ratings for English content words (nouns, verbs, and adjectives). For data collection, this megastudy used the Web-based crowdsourcing technology offered by the Amazon Mechanical Turk.