Transfer of contextual stimulus function via equivalence class development

In a conditional discrimination, 6 college students arranged six Cyrillic letters into groups of three based upon which of two additional Cyrillic letters (contextual stimuli) was present. All subjects demonstrated symmetry and transitivity within each class of equivalent stimuli. In a second conditional discrimination, two more Cyrillic letters were related to each contextual stimulus. Testing of symmetrical and transitive relations between the original contextual stimulus and the two new ones confirmed the development of two three-member classes of contextual stimuli. Subsequent tests demonstrated that the new contextual stimuli controlled the previously trained sample-comparison relations for all subjects.     

Children's identity matching and oddity: assessing control by specific and general sample-comparison relations.

After children in Experiments 1 and 2 learned identity matching or oddity, control by sample-comparison relations was assessed. Tests for generalized control displayed novel samples and two comparison stimuli, one identical to the sample. Specific relations were tested with identical or nonidentical sample-comparison stimuli from one set of stimuli and substitute comparisons from either the other training set or from a novel set. When tests displayed identical stimuli, patterns of comparison selection suggested control by generalized identity and oddity. However, selection patterns varied when stimuli were nonidentical and familiar or novel substitute comparisons were used. Therefore, control by specific relations is not a precondition for generalized identity and oddity. One set of training stimuli was used in Experiment 3, and generalized performances occurred again. Moreover, control by specific relations was shown by the oddity subjects and 2 of 6 identity subjects. Generalized and specific control may therefore exist simultaneously. In Experiment 4, selections were irregular on tests displaying substitute comparisons and samples and familiar comparison stimuli; this finding supported the relational account of specific sample-comparison control found in Experiment 3.     

Directed forgetting of elements in compound samples.

Pigeons were trained in a delayed matching-to-sample procedure in which the sample stimuli consisted of a compound of color (red or green) and spatial location (left or right). A postsample cue (houselight on or off) signaled whether color matching or location matching would be required following the delay. In Experiment 1, the reduction in performance on probe trials (in which the houselight condition was reversed relative to that on regular trials) was greater for location matching than for color matching. The birds showed overt mediational behavior during the delays on location-matching trials. On color-matching trials, the birds exhibited behavior during delays that might have interfered with that mediational behavior. In Experiment 2, the houselight condition was changed shortly before presentation of the comparison stimuli on probe trials. Accuracy of location matching was reduced when the cue initially signaled color matching and was then changed to signal location matching, whereas matching accuracy was not reduced by a change in the opposite direction. Accuracy of color matching was reduced by a change in illumination level from dark to light, regardless of type of the relevant dimension signaled by houselight illumination. Discussion of these findings focuses on the variables critical to establishment of an effective cue to forget.     

Conditional discrimination and equivalence relations: A theoretical analysis of control by negative stimuli

A detailed analysis is presented of the ways in which control by the negative stimulus in two-comparison conditional discriminations may be expected to affect the outcome of tests for the properties of equivalence relations. Control by the negative stimulus should produce the following results: (a) no observable effect on symmetry tests; (b) reflexivity test results should look like “oddity” rather than “identity”; and (c) transitivity tests that involve an odd number of nodes should yield results that are 100% opposite to tests that involve an even number of nodes. The analysis also considers the effects of variation in the type of comparison-stimulus control between and within baseline conditional discriminations. Methods are suggested for experimentally regulating the type of control, and for verifying the predictions that the analysis generates. If suggested experiments continue to support the analysis, investigators who use two-comparison conditional discriminations to study equivalence relations will either have to control explicitly whether the positive or the negative comparison governs their subjects' choices, or they will have to abandon two comparisons and use three or more comparisons instead.     

Teaching arbitrary matching via sample stimulus-control shaping to young children and mentally retarded individuals: a methodological note.

Two experiments demonstrated the efficacy of sample stimulus-control shaping programs for teaching arbitrary matching to 4 subjects who did not acquire the performances via standard methods (i.e., differential reinforcement and, in two cases, comparison intensity fading). All 4 had previously demonstrated identity matching with two-dimensional forms. Identity matching performances were then transformed into arbitrary matching by gradually changing the sample stimuli until they no longer resembled the comparison stimuli. Where applicable, these methods may have advantages over others that have been used after the failure of standard techniques.     

Classroom applications of stimulus equivalence technology

We review basic concepts and methods of stimulus equivalence research and suggest applications in teaching rudimentary language arts skills in the classroom. We describe methods of establishing equivalence-based networks of matching-to-sample, writing, and naming performances. The methods may be used as a supplement to classroom instruction to assess whether standard curriculum-based approaches establish such integrated networks. Methods derived from equivalence research may be useful for remediation when traditional teaching approaches fail. Recent research suggests that direct focus on spelling performances may be required if entire networks of language arts skills are to be acquired. In addition, the equivalence relations themselves may require concentrated teaching in some children.     

Comparison of Different Feedback Procedures in Second Language Vocabulary Learning

Research into the learning of Second Language (SL) vocabulary by beginning learners has indicated that the simultaneous presentation of the First and Second Language words results in blocking of the learning process by the familiar First Language (FL) word. Previous research also suggests that blocking by the First Language can be eliminated by bringing it in as informative feedback (either as a written or spoken word). Our experiments were designed to further extend this research. The use of a picture, either as feedback or simultaneously presented with its equivalent, along with the aural feedback and the conventional procedures were investigated in Experiment 1. Results revealed that pictures blocked the learning process less than the written FL word when both were presented with their SL referent. When used as feedback, however, pictures were not as good as the spoken FL word. Experiment 2 demonstrated that aural feedback was the best type of feedback when compared with the picture and written FL presentations, and that the picture feedback was better than the written feedback. Taken together, the results of these two studies showed that all forms of feedback overcame the problem of blocking created by simultaneous presentation of the FL and SL words, and that aural feedback was the most effective feedback procedure. It was suggested that the superiority of aural feedback was likely to be a consequence of the use of a different input channel to that of the visually presented written SL word.     

Effects of idiosyncratic stimulus variables on functional analysis outcomes.

As the methods for the functional analysis of problem behavior have continued to develop, there has been a greater focus on the specificity of controlling variables, both antecedents and consequences. Accelerating research interest in the role of antecedents reveals that a large array of stimulus variables can influence the rate of problem behavior. Indeed, the variety of these stimuli is so great that it is sometimes possible to overlook specific stimulus variables during initial assessment. The present study shows that a failure to identify these very specific (idiosyncratic) stimulus variables is serious because their presence can systematically alter the outcomes of functional analyses that are designed to assess the motivation of problem behavior. Guidelines are therefore discussed concerning when to suspect that idiosyncratic stimuli might be acting to influence assessment data, thereby promoting a search for additional stimulus variables whose identification can aid in improving the design of functional analysis conditions.     

TEACHING CHILDREN TO SPELL: DECREASING CONSONANT CLUSTER ERRORS BY ELIMINATING SELECTIVE STIMULUS CONTROL

Six elementary-aged children were taught to spell words containing initial consonant clusters (CCs). They were trained to select printed words in response to the corresponding spoken words using computerized matching-to-sample procedures. After each training session, they were tested for spelling with a constructed-response transfer test. Based on previous selective stimulus control research, we hypothesized that only the first letter of an initial CC might control spelling when CC spelling errors are made. Thus, a critical-difference matching-to-sample training condition that required the children to respond to both letters of the CC to be correct was compared to a multiple-difference training condition that required the children to respond to only one letter of the pair. Results showed that children made fewer errors during the multiple-difference training condition than during the critical-difference training condition. On the constructed-response transfer tests, however, more overall errors and CC errors were made in the multiple-difference condition than in the critical-difference condition, and the words trained in the multiple-difference condition required more training sessions to reach criterion. All children improved their spelling of novel CC words by the completion of training. If normal classroom or home reading was to be supplemented by computer tasks of the kind used here, some spelling problems could be circumvented without costly intervention by a teacher or a special trainer.     

Experimental analysis of academic performance in a classroom setting

We evaluated the effects of specific stimulus prompts on accuracy of academic performance with adolescents who displayed academic problems in a public special education classroom. We conducted analyses of instructional strategies within a multielement design with two students who had mild disabilities. Differential effects of the strategies on reading comprehension were not apparent on demand (independent-level) tasks but were apparent on high-demand (instructional-level) tasks. These results suggested that the application of experimental analysis methodologies to instructional variables may facilitate the identification of stimulus prompts associated with accurate academic performance.