Dataset bias is systematic distortion introduced when examples, labels, or populations are selected unevenly. A nationality classifier can inherit this distortion from scraped sources, broad language labels, and missing groups. section 8.2
Representation requires deliberate investigation: add data for underrepresented countries, inspect class coverage, and recognize that one surname may belong to several nationalities. Transliteration and reused spellings make the signal still less definitive. section 8.2
Inspecting a surname dataset
A surname dataset contains 37 nationality labels, including Moroccan, Arabic, Malaysian, and other categories. Sorting records, measuring unique-surname fractions, and examining overlaps reveals imbalance and conflicting labels before model training.

