The development of a standardized assessment can, in general, be broken into multiple stages. In the first, items to be used in the assessment are generated according to the skills and abilities that are to be assessed and the needs of the developers. These items are then, ideally, tested in the field on members of the population for which the assessment is intended. Item Response Theory (IRT) analysis is used to reveal items in the item pool which are unusable due to measurement error, redundancy in the level of item difficulty, or bias. More potential items may be generated and tested until there is a set of valid items with which the developers can move forward. The present study focused on the steps of item tryout and analysis for the establishment of demonstrable item-level validity. Fifty-one potential test items were analyzed for a version of the Shirts and Shoes Test (Plante & Vance, 2012) for 6-year-olds. A total of 23 items were discarded due to error in one or more of the measures mentioned above, and one item was discarded due to its low difficulty. The remaining 27 items were deemed suitable for the 6-year-old population.