The current null hypothesis is being tested with a two-tailed .05 criterion (alpha). Of course, .05 is the conventional alpha level and simply means that the experimenter is will to accept a error rate (Type I) of 5%. In general this means that there is a 5% chance that the null hypothesis will be rejected (indicating a statistical difference between the group means) even if the null hypothesis is true (there is no statistical difference between the two group means. Since the typical research hypothesis (not to be confused with the null hypothesis) is stated directionally (i.e., Group A will score higher than Group B), there may be a tendency  to think that directional research hypotheses should be tested one-tailed, whereas non-directional hypotheses (rare) should be tested two-tailed. However, I believe good judgment is used by testing both directional and non-directional hypotheses with two-tailed tests. Especially if the experimenter has an interest in rejecting the null hypothesis if it happens to be that the differences in the groups turn out to be the opposite of the prediction. However, a case can be made for using a one-tailed test when the researcher has no interest in results that turn out to be opposite of the direction predicted in the research hypothesis.