EVALUATION OF THE MULTIPLE-STIMULUS WITHOUT REPLACEMENT PREFERENCE ASSESSMENT METHOD USING ACTIVITIES AS STIMULI

The current study examined the accuracy of the multiple-stimulus without replacement (MSWO) preference assessment for identifying preferred common classroom activities as reinforcers with children with behavioral disorders. The accuracy of predictions from the MSWO regarding high, medium, and low stimulus preference was tested by providing contingent access to activities for completing math problems within an independent seatwork format. Overall, there was an interaction effect between preference ranking (high, medium, or low) and number of problems completed. The results confirm and extend previous findings regarding the accuracy of predictions with the MSWO. The findings also reveal, however, some individual differences that may account for instances in which student behavior did not conform to predictions of stimulus preference assessments.     

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.     

TRAINING STUDENTS WITH PROFOUND OR MULTIPLE HANDICAPS TO MAKE REQUESTS VIA MICROSWITCHES

In a series of three experiments, we evaluated the use of microswitches as a means for students with profound, multiple handicaps to demonstrate preferences between toys and to make requests for specific activities. In Experiment 1, 5 students learned to demonstrate toy preferences by using microswitches to activate battery-operated toys. Experiment 2 was conducted to evaluate the students' preferences for social attention. Microswitches were used to activate prerecorded messages that signaled the classroom teacher to attend to the students. In Experiment 3, the students used the switches and prerecorded messages to make specific requests of educational staff in school and community settings. Results of these experiments, evaluated within multiple baseline, alternating treatments, and simultaneous treatments designs, indicated that these students could request specific activities. Results are discussed with respect to the continued use of microswitches and to program development.     

Longitudinal analysis of leisure-item preferences.

Twenty‐two individuals with developmental disabilities participated in two leisure‐item preference assessments, spaced approximately 16 months apart. Results showed (a) an overall increase in item contact across assessments for 13 participants and (b) at least some overlap across assessments in the five most highly ranked items for every participant. These results highlight individual differences in the stability of preference over time and suggest the need for research to identify the determinants of temporal shifts in preference.     

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.     

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.     

THE USE OF BEHAVIORAL ASSESSMENT TO PRESCRIBE AND EVALUATE TREATMENTS FOR SEVERELY HANDICAPPED CHILDREN

Behavioral assessment procedures were used to prescribe and evaluate treatments of maladaptive behavior for 2 children with severe multiple handicaps. In Experiment 1, the results of an assessment of reinforcer preference were used in conjunction with a functional analysis of the conditions maintaining self-injurious behavior to prescribe a treatment for a child with severe disabilities. The treatment procedure involved the use of a pressure-sensitive microswitch to activate reinforcing stimuli during two solitary conditions, during which self-injurious behavior had occurred at high rates. The results were evaluated with a multiple baseline across settings design and indicated that self-injury decreased with concomitant increases in microswitch activation. Results were maintained at 6 weeks, 8 weeks, and 6 months. In Experiment 2, the results of behavioral assessments of reinforcer preference and self-injurious behavior were combined to develop a treatment for a second severely handicapped child, who exhibited high rates of self-injury in demand situations. This treatment was evaluated with a multiple baseline across tasks design and resulted in the elimination of self-injury for up to 15 months.     

The effects of magnitude and quality of reinforcement on choice responding during play activities

Three boys with autism participated in a study of the effects of magnitude and quality of reinforcement on choice responding. Two concurrent response alternatives were arranged: (a) to play in an area where a peer or sibling was located, or (b) to play in an area where there was no peer or sibling. During one condition, the magnitude (i.e., duration of access to toys) or quality (level of preference) of reinforcement provided for both responses was equal. During the other condition, the magnitude or quality of reinforcement was relatively greater for choosing the play area where the peer or sibling was located than the area where the peer or sibling was not located. Results showed that after repeated exposure to the unequal magnitude or quality condition, the participant increasingly allocated his responses to the play area where the peer or sibling was located. For 2 participants, this pattern of responding was maintained in the subsequent equal magnitude or quality condition. Overall, the analysis suggests that the dimensions of magnitude and quality of reinforcement can be arranged to influence choice responding in favor of playing near a peer or sibling rather than playing alone.     

Relative versus absolute reinforcement effects: implications for preference assessments

We compared results obtained in two previous studies on reinforcer identification (Fisher et al., 1992; Pace, Ivancic, Edwards, Iwata, & Page, 1985) by combining methodologies from both studies. Eight individuals with mental retardation participated. During Phase 1, two preference assessments were conducted, one in which stimuli were presented singly (SS method) and one in which stimuli were presented in pairs (PS method). Based on these results, two types of stimuli were identified for each participant: High-preference (HP) stimuli were those selected on 75% or more trials during both preference assessments; low-preference (LP) stimuli were those selected on 100% of the SS trials but on 25% or fewer of the PS trials. During Phase 2, the reinforcing effects of HP and LP stimuli were evaluated in reversal designs under two test conditions: concurrent and single schedules of continuous reinforcement. Two response options were available under the concurrent-schedule condition: One response produced access to the HP stimulus; the other produced access to the LP stimulus. Only one response option was available under the single-schedule condition, and that response produced access only to the LP stimulus. Results indicated that 7 of the 8 participants consistently showed preference for the HP stimulus under the concurrent schedule. However, when only the LP stimulus was available during the single-schedule condition, response rates for 6 of the 7 participants were as high as those observed for the HP stimulus during the concurrent-schedule condition (1 participant showed no reinforcement effect). These results indicate that, although the concurrent-schedule procedure is well suited to the assessment of relative reinforcement effects (preference for one reinforcer over another), absolute reinforcement effects associated with a given stimulus may be best examined under single-schedule conditions.     

EMERGENCE OF REINFORCER PREFERENCE AS A FUNCTION OF SCHEDULE REQUIREMENTS AND STIMULUS SIMILARITY

Tustin (1994) recently observed that an individual's preference for one of two concurrently available reinforcers under low schedule requirements (concurrent fixed-ratio [FR] 1) switched to the other reinforcer when the schedule requirements were high (concurrent FR 10). We extended this line of research by examining preference for similar and dissimilar reinforcers (i.e., those affecting the same sensory modality and those affecting different sensory modalities). Two individuals with developmental disabilities were exposed to an arrangement in which pressing two different panels produced two different reinforcers according to progressively increasing, concurrent-ratio schedules. When two dissimilar stimuli were concurrently available (food and a leisure item), no clear preference for one item over the other was observed, regardless of the FR schedules in effect (FR 1, 2, 5, 10, and 20). By contrast, when two similar stimuli were concurrently available (two food items), a clear preference for one item emerged as the schedule requirements were increased from FR 1 to FR 5 or FR 10. These results are discussed in terms of implications for conducting preference assessments and for selecting reinforcers to be used under training conditions in which response requirements are relatively high or effortful.