Suppose that a researcher wants to know if a new teaching method is more effective than the old one. What would the research hypothesis be?
Ho: no difference, method1 = method2 (null hypothesis)
Ha: method1 ≠ method2
The above is if you would also want to know if the second method is worse (two-tailed).
If you only want to consider it being better (one-tailed), then:
Ha: method1 < method2