This pamphlet describes the exciting potential of item banking--a new approach to testing which combines both comparability of scores with flexibility of test format. Item banks are collections of items where the characteristics of each item is known and these characteristics can be summated to described a test made from such items. The principle behind the calibration of such items is explained in relation to the Rasch model. The use of item banks provides more flexible and appropriate tests than traditional standardized tests. Although in theory the Rasch model suggests exciting possibilities for the future of achievement testing, there are still some practical problems to be solved. (Author/CTM)