Skillet (band) Skillet (band) Skillet is an American Christian rock band formed in Memphis, Tennessee in 1996. The band currently consists of husband John (lead vocals, bass) and wife Korey Cooper (rhythm guitar, keyboards, backing vocals) along with Jen Ledger (drums, vocals) and Seth Morrison (lead guitar). The band has released ten albums, with two, "Collide" and "Comatose", receiving Grammy nominations. Two of their albums, "Comatose" and "Awake", are certified Platinum and Double Platinum respectively by the RIAA while "Rise" is certified Gold . Skillet went through several line-up changes early in their career, leaving founder John Cooper as the only original
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