Parziale vs. prevenuto vs. di parte

The Italian words 'parziale', 'prevenuto', and 'di parte' all relate to bias or partiality, but they have subtle differences in usage and connotation.

Parziale

'Parziale' means partial or incomplete, often used to describe a lack of objectivity or fairness, but can also mean 'partial' in the sense of 'incomplete'.
Il giudice ha dato un giudizio parziale.
(The judge gave a biased judgment.)
Abbiamo ricevuto solo un pagamento parziale.
(We received only a partial payment.)

Prevenuto

'Prevenuto' implies a prejudiced or preconceived notion, often based on insufficient knowledge or experience.
Era prevenuto contro gli stranieri.
(He was prejudiced against foreigners.)
Non essere prevenuto, ascolta prima la sua versione.
(Don't be biased, listen to his version first.)

Di parte

'Di parte' literally means 'of a party' and is used to describe someone or something that is partisan or biased in favor of a particular group or viewpoint.
Quel giornale è noto per essere di parte.
(That newspaper is known for being partisan.)
Ha fatto un'analisi di parte della situazione.
(He made a biased analysis of the situation.)

Summary

While all three words relate to bias, 'parziale' can mean both biased and incomplete, 'prevenuto' emphasizes prejudice based on preconceptions, and 'di parte' specifically refers to partisan bias or taking sides.