significance; statistical significance
Technical term used mainly in statistics and mathematics to indicate that a result is unlikely to have occurred by chance.
We need to test the significance of this data.
The hypothesis was rejected because no significance was found.
有意差 specifically means 'significant difference', a common term in hypothesis testing, whereas 有意性 is the broader concept of significance.
significance test; test of significance
Compound of 有意 (yūi, 'significant') + 性 (-sei, '-ness'), a standard Sino-Japanese nominalization pattern.