Question

In a two group between-subjects experiment, if the effect of the independent variable increases, what would happen to the absolute value of the obtained t-statistics an what would happen to the critical value of t? In a two group between subjects experiment, if the effect of the independent variable increases, what would happen to the direction of the independent variable? In a two group between subjects experiment, if the standard deviation of the dependent variable increases, what would happen to the absolute value of cohen's d?

Answer 1

1. If the effect of independent variable increases, this means that independent variable has significant contributions to explain the variability of dependent variable. So if the effect of independent variable increases then its t-value will lie outside the critical region. Let say we take 95% confidence interval with 5 percent significance level then absolute t-value will be greater than 2.

2. If there is positive relation between dependent and independent variable then dependent variable will increase if the effect of independent variable increases . So there should be positive direction.

If there is a negetive relation between dependent variable and and independent variable then dependent variable will decrease as effect of independent variable increases. Here is a negetive direction between dependent and independent variable.

3.if the standard variable increases then absolute cohen's d value will be very small. This means there is no significant difference between two groups subject experiment.

Cohen's d =(difference between mean of two group) /( standard deviation) . So if standard deviation is very large then cohen's d will very small and its absolute value lie with in the critical region.