Database from Stanford study of children's vocabulary development (downloaded here: http://wordbank.stanford.edu/) Shows how kids' passive and active vocabulary grow throughout the years. Contains data of 84,138 children from 38 countries.

Data dictionary:

• 'language' - language that child learns. Categorical.
• 'age' - child’s age. Quantitative.
• 'comprehension' - how many words child can understand. Quantitative.
• 'production' - how many words child says. Quantitative.
• 'sex' - child’s sex. Categorical.

The following information could be visualized:

1. In what age difference between production and comprehension decreases? How that differes by language?
2. What is the difference between comprehension in girls and boys? How that differs by language?