They should be written like this: 1.Compared to last term, she has made great progress. 2.Compared to investing,savings involves no risk. 3.When comparing this term to the last, you will see that she has made great progress. 4.When comparing investing and savings, you will see that saving does not involve any risk whereas investing does.

Comparing is in the progressive aspect - here it suggests something underway and puts emphasis on the person making the comparison. Compared is in the simple aspect. In practice the two statements given are very close in meaning, although the first emphasises the person making the comparison, and the second gives more of an 'objective' appearance. Hope this helps.

You can also use 'better than' and 'less...than' 1. This semester was better than the the last one. 2. Saving is less risky than investing.

Rightly said David, figuratively you may use anyone.