Overall, are the selected funds sufficiently different from each other so that the portfolio achieves a
low overall correlation?
Overall the correlations between maternal glucose during pregnancy and BMI Z score at age 2 years were weak (fasting glucose r = 0.05, P = 0.08; 1 - h glucose r = 0.04, P = 0.22; 2 - h glucose r = 0.03, P = 0.36; and area under the curve for glucose r = 0.04, P = 0.18).
Others questioned whether the tremendous effort to observe teachers in classrooms, given its
weak overall correlation to achievement, was worth it (Greene, 2013).
Overall correlations were significant for precentral and postperipheral saccade aligned activity and increased from 0.050 and 0.076 to 0.145 and 0.157, respectively.
This would cause
the overall correlation to be biased downward, and lower than that observed among students responding to surveys within the same school environment.
This results in
an overall correlation in the simulation of r = 0.24, with a very small p - value (i.e. a very small chance that a correlation of this size would be observed by random chance alone if the true correlation was zero).
The only other association that reached statistical significance was between categories of maternal 1 - h glucose and a BMI Z score at 2 years ≥ 85th percentile (χ2 for trend = 5.32, df = 1, P = 0.017), but
the overall correlation between maternal glucose during pregnancy and BMI Z score at age 2 years was weak (fasting glucose r = 0.05, P = 0.08; 1 - h glucose r = 0.04, P = 0.22; 2 - h glucose r = 0.03, P = 0.36; and area under the curve r = 0.04, P = 0.18).