N4
とかんがえられている
Is considered, Is thought of as
カバは世界で最も危ない動物だと考えられている。
Hippos are thought to be the most dangerous animal in the world.
Explanation
「〜と考えられている」 means 'is thought to be …'. It presents a view as the shared opinion of scholars or people in general, not as 'I think'. It is common in papers, news and writing: 「ストレスは病気の主な原因と考えられている」 (Stress is thought to be a main cause of illness). The view usually rests on experiments, discoveries, argument or surveys.
Mixed up with
The three objective phrases: 「〜と考えられている」 is a view or consensus reached by thinking, reasoning or research; 「〜とされている」 is officially or authoritatively fixed; 「〜といわれている」 is what people say, passed along by word of mouth.
「と思われている」 can be used in the same place.