↑ “correlation coefficient”. NCME.org. National Council on Measurement in Education. Truy cập ngày 17 tháng 4 năm 2014. correlation coefficient: A statistic used to show how the scores from one measure relate to scores on a second measure for the same group of individuals. A high value (approaching +1.00) is a strong direct relationship, values near 0.50 are considered moderate and values below 0.30 are considered to show weak relationship. A low negative value (approaching -1.00) is similarly a strong inverse relationship, and values near 0.00 indicate little, if any, relationship.
↑ Boddy, Richard; Smith, Gordon (2009). Statistical methods in practice: for scientists and technologists. Chichester, U.K.: Wiley. tr. 95–96. ISBN978-0-470-74664-6.
