You Have Just Finished a Unit on Basic Material That

You have just finished a unit on basic material that you want your students to know thoroughly before you proceed to more difficult material.You construct what you believe is a challenging test over the material and administer it to your class.You then score the test and conduct an item analysis.You find that item difficulty values for all the items are between .90 and 1.00.You should conclude that:

A) Low-achieving students did better on the test questions than high-ability students did, so you may have errors in your scoring key.
B) On the average, the test was moderately difficult for students, so perhaps some students know the material and others do not.
C) The test questions were extremely difficult for students, so you probably should devote additional instructional time to the material.
D) The test questions were easy for students, so apparently your class has learned the material well.