Zuò yánjiū zuì yàojǐn de shì bù zhī wéi bù zhī, bùkě qiǎng bùzhī yǐwéi zhī.
In research, the most essential thing is to admit what you don't know - never force ignorance into knowledge.
Tips
history
From 《论语·为政》 (Analects: On Governance). Confucius tells his student Zilu: 知之为知之,不知为不知,是知也 - 'to know when you know, and to know when you don't know - that is true knowing.' A cornerstone of Confucian intellectual honesty.
usage
Almost always quoted as the second half of the couplet 知之为知之,不知为不知. Used to praise humility in learning or to rebuke bluffing.