Answer:
Replication.
Explanation:
Tiffany has duplicated the study using Sheldon's original methodology to see if her results are compatible to Sheldon's. Such a study illustrates the concept of replication. Replication is one key aspect of the scientific method. As Tiffany used the original methodology to see if she obtains the same results she is duplicating the original study. Her results will be relevant in the area because she is an independent researcher.