1. Third person singular preterite of 'pesquisar' with reflexive or impersonal pronoun 'se', indicating a research action was performed in an unspecified or general manner
Research was conducted on the topic.
Pesquisou-se sobre o assunto.
2. Used in passive voice construction or impersonal context to indicate that research took place without specifying the exact agent
They researched the effectiveness of the new method.
Pesquisou-se a eficácia do novo método.