A comparison of verbal and tangible stimulus preference assessment methods in adults with schizophrenia

Verbal stimulus preference assessments were compared with tangible stimulus preference assessments for four adults with a diagnosis of schizophrenia. In the verbal assessment, participants were asked, ‘Do you want X or Y?’, the items were not present, and the participant chose an item verbally. In the tangible assessment, pairs of items were placed in front of the participant and s/he was asked to choose by approaching the stimuli. The two assessment methods yielded identical highest preference items for three of the four participants and identical lowest preference items for all participants. In addition, the verbal assessment method took less time to complete than the tangible assessment method. Copyright © 2003 John Wiley & Sons, Ltd.     

The impact of high- and low-preference stimuli on vocational and academic performances of youths with severe disabilities

Pictorial and tangible paired-stimulus preference assessments were compared with 4 adolescents with developmental disabilities. In the tangible assessment, two stimuli were placed in front of the participant on each trial; in the pictorial assessment, two line drawings were placed in front of the participant on each trial. Approach responses were recorded for each assessment. The assessments generated similar preference hierarchies for all participants. Reinforcer assessments confirmed that response rates were higher when access to high-preference items was available than when low-preference items were available. Implications for assessing preferences and selecting items to be used in training programs are discussed.     

Assessing object-to-picture and picture-to-object matching as prerequisite skills for pictorial preference assessments

Tangible and pictorial paired-stimulus (PPS) preference assessments were compared for 6 individuals with developmental disabilities. During tangible and PPS assessments, two edible items or photographs were presented on each trial, respectively, and approach responses were recorded. Both assessments yielded similar preference hierarchies for 3 participants who could match pictures and objects but different hierarchies for 3 participants who could not. Reinforcer assessments verified that items identified as high preference on PPS assessments functioned as reinforcers only for participants with matching skills.     

The effects of providing access to stimuli following choice making during vocal preference assessments

Two variations of a vocal paired-stimulus preference assessment were evaluated to determine whether the verbal reports of preference, given by individuals with developmental disabilities when no access to the activity was given, matched their verbal reports when access to the activity was given contingent on their choice. The results indicated different outcomes between the two methods for 6 of the 7 participants. Subsequent reinforcer assessments, conducted for 2 participants, showed that activities identified in the preference assessments that provided access contingent on selection resulted in more responding than did activities identified in the preference assessment that did not include access to items following their selection.     

The effects of establishing operations on preferences for tangible items

Researchers have demonstrated that both deprivation and satiation can affect the outcome of preference assessments for food. In the current study, paired-stimulus preference assessments for tangible items were conducted under three conditions: control, deprivation, and satiation. Three persons with developmental disabilities and 3 typically developing preschool children served as participants. The results demonstrated that deprivation and satiation influenced the outcome of preference assessments of leisure items or toys.     

An Evaluation of a Brief Multiple-Stimulus Without Replacement Preference Assessment Conducted in an Electronic Pictorial Format

We compared the results of a brief electronic pictorial multiple-stimulus without replacement (EP-MSWO) preference assessment to a brief tangible MSWO preference assessment in five children with autism. Results of both assessments yielded a match between high preferred (HP) toys for four participants and low preferred toys for three participants. The overall correlation between assessments across participants was strong and statistically significant (ρ = .67, p < .01). A reinforcer assessment conducted with three participants confirmed HP toys identified in the EP-MSWO functioned as reinforcers.     

Further examination of video‐based preference assessments without contingent access

The first purpose of this study was to attempt to replicate previous findings that video‐based preference assessments without access to selected stimuli may accurately predict relative reinforcing efficacy of stimuli. To do this, we conducted a concurrent operant reinforcer assessment in which we evaluated the relative reinforcing value of highly preferred and less preferred items identified in a video‐based preference assessment. The second purpose of this study was to begin to evaluate the potential behavioral mechanisms responsible for the validity of this assessment. To conduct this analysis, we evaluated the relative reinforcing value of those same stimuli depicted in video format and then compared results to results obtained during the reinforcer assessment for tangible stimuli. For all five participants, stimuli identified as highly preferred functioned as reinforcers, and four of five participants, responding during the reinforcer assessment was similar in the presence of tangible stimuli and videos depicting those stimuli.     

An examination of stimulus technology level and preference displacement during multiple stimulus without replacement preference assessments

Researchers have observed that preference for edible items may displace preference for leisure items when items from the stimulus classes are assessed together within multiple stimulus without replacement (MSWO) preference assessments. The current study extends previous research by examining patterns of preference and displacement when assessing preference for high-tech and low-tech leisure items. We conducted three separate MSWO preference assessments; one assessing low-tech items, another assessing high-tech items, and a combined assessment (using the top four high- and low-tech items from the previous assessments) to test for displacement. Preference for high-tech items fully or partially displaced preference for low-tech items in five of eight participants. We then conducted concurrent and single operant reinforcer assessments using the highly preferred high-tech and low-tech items. Reinforcer assessment results demonstrated similar levels of responding for the highest preferred high-tech and low-tech items, indicating that combining high- and low-tech items within preference assessments may influence the validity of results.     

Preference for leisure items over edible items in individuals with dementia: A replication

We replicated previous research in which adults with dementia tended to show a preference for leisure items over edible items when presented in the same array. Additionally, we conducted engagement analyses with the highest, middle, and lowest preference leisure items to determine whether relative preference corresponded to engagement in the natural environment. The most highly preferred stimulus for 6 out of 7 participants was a leisure item, and for each of those six the top 3 preferred stimuli were leisure stimuli. For 4 participants, the most preferred stimulus also produced the longest duration of engagement. We discuss the issues we encountered when conducting preference assessments with adults with intact vocal verbal repertoires, and suggest potential explanations for the displacement of edibles by leisure stimuli in older adults with dementia.     

Stimulus preference assessments and the utility of a moderate category

Recent studies have shown that moderate (Piazza, Fisher, Hagopian, Bowman, & Toole, 1996 ) and low (Taravella, Lerman, Contrucci, & Roane, 2000 ) ranked items on stimulus preference assessments may function as reinforcers. Following an initial preference assessment the current study analyzed whether moderate or low preference items were more likely to be ranked as high preference on subsequent preference assessments. Results show that for five of the seven participants additional high preference items were identified from the moderate preference set, while additional high preference items were identified from the low preference set for only one participant. Results are discussed in terms of the need to identify multiple reinforcers and the composition of the stimulus array during preference assessment. Copyright © 2006 John Wiley & Sons, Ltd.     

Some determinants of changes in preference over time

Results of longitudinal studies suggest that the stability of preferences varies across individuals, although it is unclear what variables account for these differences. We extended this work by conducting periodic assessments of preference for leisure activities over 3 to 6 months with 10 adults with developmental disabilities. Although previous research has collectively shown that preferences identified via repeated assessment are highly variable, our results showed that preferences were relatively stable for the majority (80%) of participants. In an attempt to identify some environmental determinants of shifts in preference, we provided extended daily access to high-preference items (preference-weakening manipulation) and paired access to low-preference items with social and edible putative reinforcers during brief sessions (preference-strengthening manipulation). Preference assessments continued over the course of these manipulations with 2 participants. Results showed that changes in preference across time could be produced systematically and suggest that naturally occurring changes in establishing operations or conditioning histories contribute to temporal shifts in preference. Implications for preference assessments, reinforcer usage, and planned attempts to change preferences are discussed.     

Examination of relative reinforcement effects of stimuli identified through pretreatment and daily brief preference assessments.

Several brief preference assessments have recently been developed to identify reinforcers for individuals with developmental disabilities. One purported advantage of brief assessments is that they can be administered frequently, thus accommodating shifts in preference and presumably enhancing reinforcement effects. In this study, we initially conducted lengthy paired‐choice preference assessments and identified a hierarchy of preferred items for 5 individuals with developmental disabilities. Subsequently, brief multiple‐stimulus‐without‐replacement assessments using the same items were completed each day prior to work sessions. On days when results of the daily brief assessment differed from the one‐time lengthy assessment, the relative reinforcing effects of the top items from each assessment were compared in a concurrent‐schedule arrangement. The results revealed that when the two assessments differed, participants generally allocated more responses to the task associated with the daily top‐ranked item.     

Long‐term stability of edible preferences in individuals with developmental disabilities

Multiple stimulus without replacement (MSWO) preference assessments were used to examine the stability of preference hierarchies in eight individuals with developmental disabilities. In Study 1, preference assessments using edible items were conducted 6 months apart; in Study 2, assessments were conducted 12 months apart. As in previous studies analyzing preference stability, individual differences in stability were found in both studies. However, mean rank order coefficients across participants revealed interesting findings in both comparisons. Generally, preference for edible items, particularly the most and least preferred stimuli, was more stable across time than has been found in other research conducted with leisure items. Stability was greater when only 6 months lapsed between assessments. Moreover, for three of the eight participants, rank order coefficients were significant across both studies indicating the possibility that some individuals may tend toward more stable preferences. Copyright © 2007 John Wiley & Sons, Ltd.     

Further evaluation of the use of preference categories to identify novel reinforcers: A systematic replication

Preference assessments are frequently used to identify reinforcers for individuals with autism spectrum disorder and intellectual and developmental disabilities. Although well‐established procedures have been shown to identify preferred stimuli for individual items that can be used in skill acquisition and behavior reduction programs, little research has been conducted on identifying categories of preferred items. In this study, paired‐stimulus preference assessments were conducted with 4 individuals with autism spectrum disorder. Researchers classified the edible stimuli as belonging to 1 of 4 categories: chocolate (e.g., chocolate chips and M&M's^®), salty/crunchy (e.g., chips and crackers), gummy (e.g., Swedish Fish^® and Starburst^®), or fruit/vegetable (e.g., grape and apple). Preference hierarchies were identified for individual stimuli and for categories of stimuli. For all participants, at least 3 of the 4 most preferred items came from the same category. Novel items (i.e., items not included in the preference assessments) identified by the researchers as belonging to the high‐preference category functioned as effective reinforcers during subsequent reinforcer assessments for all participants. This finding suggests that clinicians could identify likely effective edible reinforcers based on an individual's categorical preference without explicit testing.     

Preliminary investigation of a video-based stimulus preference assessment

Video clips may be an effective format for presenting complex stimuli in preference assessments. In this preliminary study, we evaluated the correspondence between preference hierarchies generated from preference assessments that included either toys or videos of the toys. The top-ranked item corresponded in both assessments for 5 of the 6 participants, and the top- and bottom-ranked items corresponded for 4 participants. The implications of these results for future research on video preference assessments are discussed.     

DISPLACEMENT OF LEISURE REINFORCERS BY FOOD DURING PREFERENCE ASSESSMENTS

Identification of reinforcers for individuals with developmental disabilities is often based on the outcome of preference assessments in which participants make selections from among a variety of items. We determined the extent to which individuals might show a general preference for food items over leisure items during such assessments and whether leisure items that are “displaced” by food items might nevertheless function as reinforcers. Arrays consisting of food items only and then nonfood items only were presented separately to 14 participants and then were ranked to determine preference. The top selections from these initial assessments were subsequently combined in a third assessment, and preferences were again established. All but 2 participants showed a general preference for food items, such that selection of nonfood items in the combined arrays was displaced downward relative to selection of nonfoods in the nonfood-only arrays. Two of the participants were exposed to a condition in which a nonfood item was delivered contingent on the occurrence of an adaptive response, and increased rates of responding by both individuals were observed. Results are discussed in terms of limitations posed by using only food items as reinforcers and the resulting need to take precautionary measures when attempting to identify nonfood reinforcers.     

A COMPARISON OF REINFORCER ASSESSMENT METHODS: THE UTILITY OF VERBAL AND PICTORIAL CHOICE PROCEDURES

We compared three methods of stimulus preference assessment for verbal children and specifically evaluated the utility of a verbal choice procedure for assessing relative reinforcer value. Using a token system, relative preference for five categories of reinforcers, representing 15 different stimuli, was assessed by three methods: a reinforcer survey, a verbal stimulus-choice questionnaire, and a pictorial stimulus-choice procedure. Results showed that the verbal and pictorial stimulus-choice assessments accurately identified high- and low-preference categories for 3 of 4 participants. Survey results alone often rated multiple categories as high preference, were less likely to identify low-preference categories, and were less likely to correspond with the results of a reinforcer assessment.     

Evaluating the predictive validity of a single stimulus engagement preference assessment.

Most preference assessments require individuals to choose among two or more stimuli. More recently, the duration of engagement with items has been used as an index of preference. In the current study, the predictive validity of a single stimulus engagement (SSE) preference assessment was evaluated with 4 individuals. Stimuli were presented singly for a brief period while engagement with that stimulus was recorded. Although SSE preference rankings closely matched paired stimulus preference assessment rankings for only 2 of the 4 participants, relative preference rankings based on duration of engagement predicted relative reinforcer effectiveness for all participants in a subsequent concurrent‐schedule reinforcer assessment. The SSE procedure took less time to administer than the paired stimulus procedure but produced less stable preference rankings across administrations. The SSE procedure may be appropriate for individuals who have difficulty selecting one stimulus from among two or more stimuli, and it may be well suited for evaluating activities that are difficult to present in a paired stimulus format.     

Use of a latency‐based demand assessment to identify potential demands for functional analyses

Unlike potential tangible positive reinforcers, which are typically identified for inclusion in functional analyses empirically using preference assessments, demands are most often selected arbitrarily or based on caregiver report. The present study evaluated the use of a demand assessment with 12 participants who exhibited escape‐maintained problem behavior. Participants were exposed to 10 demands, with aversiveness measured by average latency to the first instance of problem behavior. In subsequent functional analyses, results of a demand condition that included the demand with the shortest latency to problem behavior resulted in identification of an escape function for 11 of the participants. In contrast, a demand condition that included the demand with the longest latency resulted in identification of an escape function for only 5 participants. The implication of these findings is that for the remaining 7 participants, selection of the demand for the functional analysis without using the results of the demand assessment could have produced a false‐negative finding.     

Teacher report and direct assessment of preferences for identifying reinforcers for young children

Teachers were asked to identify and rank 10 preferred stimuli for 9 toddlers, and a hierarchy of preference for these items was determined via a direct preference assessment. The reinforcing efficacy of the most highly preferred items identified by each method was evaluated concurrently in a reinforcer assessment. The reinforcer assessment showed that all stimuli identified as highly preferred via the direct preference assessment and teacher rankings functioned as reinforcers. The highest ranked stimuli in the direct assessment were more reinforcing than the teachers' top-ranked stimuli for 5 of 9 participants, whereas the teachers' top-ranked stimulus was more reinforcing than the highest ranked stimulus of the direct assessment for only 1 child. A strong positive correlation between rankings generated through the two assessments was identified for only 1 of the 9 participants. Despite poor correspondence between rankings generated through the teacher interview and direct preference assessment, results of the reinforcer assessment suggest that both methods are effective in identifying reinforcers for toddlers.