Skillet (band) me." Skillet's album "Comatose" was released on October 3, 2006. It features the singles "Rebirthing," "Whispers in the Dark," "Comatose," "The Older I Get," "Those Nights," "The Last Night", and "Better Than Drugs". The album debuted at No. 55 on the "Billboard" 200 and No. 4 on the US Top Christian Albums chart. In January 2008, Skillet announced that their drummer, Lori Peters, was retiring from the band, feeling that "it's time for her to come off of the road and start a new chapter in her life." Peters' last concert with Skillet was on December 31, 2007. However, during
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