The number 1 ranked items is… 10. Correctly calculate the percentage of intervals each item is manipulated. 11. Identify the corresponding rank for each item. Once you end your session, allow the child to engage with the items while you calculate and identify the item that is most preferred. First you will calculate the percentage of intervals that each item was manipulated (including intervals in which two or more items were manipulated). The formula for calculating the percentage of intervals for each item is located at the bottom of the data sheet which states to divide the number of intervals the item was selected by the total number of intervals, which is 30, and multiply by 100. In this example, the client was observed manipulating item 1, bear during 1 out of the 30 intervals which equals 3%. Item two, playdoh was manipulated during 22 out of the 30 intervals. Item 3, car, was manipulated during 2 out of the 30 intervals. Item 4, maraca, was manipulated during 9 out of the 30 intervals, and the client was never observed engaging with item 5, book, and therefore has a percentage of 0. Once you have calculated the percentage for each item, identify the corresponding rank from 1 being the highest percentage to 5 being the lowest percentage. If 2 or more items equal the same percentage, rank those items with the same number. For example, if item one and five were both manipulated during 3% of the intervals, then both of these items would be ranked at number 4 and there would be no number 5 ranking. The number one ranked item is considered the most preferred item and is most likely to serve as a reinforcer during your regularly scheduled time with your client. In this example, playdoh has been identified as the number one ranked item and is therefore is the most preferred item. The number 1 ranked items is… Item 2: Playdoh 1/30 22/30 2/30 9/30 0/30 4 1 3 2 5