For example: "The purpose of the experiment was to determine whether listening to the sound of waves relaxes people more than listening to Mozart."
For example: "The researcher measured the subjects' blood pressure, heart rate, and brain waves, using an EEG recording, before the treatment session. For the treatment, one group of subjects listened to a relaxation tape that consisted only of the sound of waves crashing on a beach for 10 minutes. Another group of subjects listened to the second movement of Mozart's "Ein Kleinen Nachtmusik". Then the researcher repeated the same measurements that were taken before the treatment."
For example: "The researcher assumed that a decrease in blood pressure or heart rate indicates an increase in relaxation. Also, a change in brain waves to include more delta waves also indicates an increase in relaxation. Therefore, the researcher will examine whether any of his measures changed from before to after the treatment in such a way as to indicate that the treatment produced any relaxation. If so, then the amount of relaxation produced by the two treatments will be compared. Either of two findings will support the researcher's hypothesis. The researcher predicts that either the sound of waves will produce relaxation whereas the Mozart will not, or that they will both produce relaxation, but the waves will produce significantly more relaxation than the Mozart."