Read the transcript (below) Read the following scenario You are working on developing a token economy for a 4-year-old girl. You need to come up with a list of possible backup reinforcers to use. You already have a list of activities to use as reinforcers but you want some ideas for inexpensive items to use. Develop a list of 10 items to be used in a stimulus preference assessment. Describe the paired stimulus preference assessment and how to implement a paired stimulus preference assessment using the items you identified. How will you know which items are preferred? Describe the two types of multiple stimulus preference assessments. Select one type to use and provide your rationale for your choice. Describe how you would implement this assessment using the items you selected. How will you know which items are preferred? Why are the results of a stimulus preference assessment not necessarily guaranteed reinforcers? Transcript Welcome to our Unit 5 Discussion Board! This week, you read about group contingencies and token economies. For your group contingencies and token economies to work, you need to use effective reinforcers. How do you find effective reinforcers? You start with a preference assessment to find out what your client likes and doesn’t like. You then test out these preferences using a reinforcer assessment. These are our topics for this lecture. There are a variety of ways that you can determine your client’s preferences. The first (and easiest) way is to simply ask the person. Not only is this the easiest way to determine preferences, but it is the quickest way, too. You can ask your client open-ended questions like, “What do you like to do for fun?” Or “What is your favorite food?” Asking your client to self-report preferences requires that your client have the verbal skills to do so. If your client does not have the verbal skills to self-report on preferences, you can ask the client’s significant others such as parents or teachers. One of my favorite ways to get an idea of a client’s preferences is to just hang out and watch what the client chooses to do with his or her free time. The activities that a person freely chooses to engage in will often be effective reinforcers in behavior plans. You can do this in a contrived way (where you set up the environment with a predetermined set of activities and materials) or you can do it in a natural way (where you observe the client in his or her everyday environment). In a trial-based method of assessing stimulus preference, various stimuli are presented to the client in a series of trials. The client’s response to each stimulus is measured. When you are measuring the client’s response, you are looking for approach, contact, and engagement with the item. Approach would be defined as looking at the item or reaching for the item. Contact would be defined as touching the time. Engagement would be defined as actually interacting with the stimulus (playing with it, eating it if it is a food item). The item or items that are approached, contacted, or engaged with during the highest number of trials are assumed to be the most preferred item or items. There are several different ways you can present items in the trial-based stimulus preference assessments. In the single stimulus presentation method, only one item is presented at a time. If a client has difficulty selecting among an array of items, the single stimulus presentation is probably best. In the paired stimuli presentation method, each trial consists of two items presented together. The client is required to choose among the two. Throughout the assessment, each stimulus is matched randomly with all the other stimuli in the set so that each stimulus gets paired with every other stimulus at least once. At the end of the assessment, the stimuli are rank ordered from high-preference (the item chosen the greatest number of times) to lowest preference (the item chosen the least number of times or not chosen at all). Multiple stimuli preference assessments are very similar to paired stimuli preference assessments. The main difference is that an array of 3 or more stimuli are presented together instead of just two. There are two variations of the multiple stimuli preference assessment – multiple stimuli preference assessment with replacement and multiple stimuli preference assessment without replacement. In a multiple stimuli with replacement preference assessment, after the client chooses an item from the array, that item is replaced with another item. For example, in an array of 6 items, the client is always choosing from 6 items. In a multiple stimuli without replacement preference assessment, after the client chooses an item from the array, that item is not replaced. Continuing with our example, in an array of 6 items, after the first trial in which the client chooses an item, then the array goes down to 5 items, after the second trial in which another item is chosen, then the array goes down to 4 items, and so on. Just because an item or activity is preferred does not mean that a client will work to access it. The only way to know for sure that an item or an activity will function as a reinforcer is to present the item or activity immediately following a behavior and see if that behavior increases in the future. You want to find out if that item functions as a positive reinforcer in real life. Your reading describes a variety of reinforcement schedules to test the effectiveness of an item or activity to act as a reinforcer. The main takeaway from this is that you want to make sure a client will work for an item or activity before plugging it into a behavior plan. You cannot just assume that because the item is preferred the client will engage in a new behavior to get access to it.