Skillet (band) during September and October 2016. In December 2016, a 27-city, second leg of the tour was announced. Opening for Skillet on this second leg were Sick Puppies and Devour the Day. In 2017, Skillet opened for Korn and Stone Sour on the second half of The Serenity of Summer Tour which started in Syracuse, New York on July 19 and finished in Cleveland, Ohio August 2. Starting November 5, 2017, Skillet joined Britt Nicole, Colton Dixon, Tauren Wells, and Gawvi for five shows on the Air1 Hits Tour across the central United States. In 2018, Skillet headlined the Winter Jam
Differential item functioning Differential item functioning Differential item functioning (DIF) is a statistical characteristic of an item that shows the extent to which the item might be measuring different abilities for members of separate subgroups. Average item scores for subgroups having the same overall score on the test are compared to determine whether the item is measuring in essentially the same way for all subgroups. The presence of DIF requires review and judgment, and it does not necessarily indicate the presence of bias. DIF analysis provides an indication of unexpected behavior of items on a test. An item does not display DIF if