Not following, may help if you provide your example. The p-value is the probability of getting a value (parameter) that extreme given that there really exist not relationship. Are you talking about your t-statics or p-values? T-statistic is the difference over the standard error, which is the number of standard deviations the groups differs from the other group. So typically if it is around 2 standard deviation different in either direction, we say the probability is low for that extreme of a difference under the pretenses that the two groups are equal.