After submitting a résumé by mail, how long should you wait before following up with an employer?

Russell's study compared gpa of those students who volunteered for academic study skills training and those who did not elect to take the training. he found that those who had the training also had higher gpa. with which validity threat should russell be most concerned?

Advertisers like online advertising because

The strategy of first determining what the market is willing to pay, then subtracting a desired profit margin to determine a desired cost of production is called