
81Analysis of Data to Determine Association and Agreement
time; if the sign of the coefcient is negative, as one variable increases, the
other decreases.
Interpretation of the value of the coefcient is somewhat subjective, and one
should exercise caution in interpreting the size of the coefcient to mean statis-
tical signicance. Statistical signicance indicates retention or rejection of the
null hypothesis, whereas the size of the coefcient indicates the strength of the
correlation. The closer the coefcient is to ±1, the stronger the relationship. One
rule for interpreting the strength of a correlation is that coefcients ≥ 0.80 indi-
cate ...