Limits to preference and the sensitivity of choice to rate and amount of food

Studies of choice holding food‐amount ratio constant while varying food‐rate ratio within sessions showed that local changes in preference depend on relative amount of food. The present study investigated whether sensitivity of choice to food‐rate ratio and sensitivity to food‐amount ratio are independent of one another when food‐rate ratios are varied across sessions and food‐amount ratios are varied within sessions. Food deliveries for rats’ presses on the left and right levers were scheduled according to three different food‐rate ratios of 1:1, 9:1, and 1:9; each food‐rate ratio lasted for 106 sessions and was arranged independently of seven food‐amount ratios (7:1, 6:2, 5:3, 4:4, 3:5, 2:6, and 1:7 food pellets) occurring within sessions in random sequence. Each amount ratio lasted for 10 food deliveries and was separated from another by a 60‐s blackout. Sensitivity to rate ratio was high (1.0) across food deliveries. Sensitivity to amount ratio was low when food rates were equal across alternatives, but was high when rate ratio and amount ratio opposed one another. When rate ratio and amount ratio went in the same direction, choice ratio reached an elevenfold limit which reduced sensitivity to approximately zero. We conclude that three factors affect sensitivity to amount: (1) the limit to preference, (2) the equal effect on preference of amounts greater than four pellets, and (3) the absence of differential effects of switches in amount in the equal‐rates (1:1) condition. Taken together, these findings indicate that rate and amount only sometimes combine independently as additive variables to determine preference when amount ratios vary frequently within sessions.     

Examination of efficacious,efficient, and socially valid error‐correction procedures to teach sight words and prepositions to children with autism spectrum disorder

Prior research shows that learners have idiosyncratic responses to error‐correction procedures during instruction. Thus, assessments that identify error‐correction strategies to include in instruction can aid practitioners in selecting individualized, efficacious, and efficient interventions. The current investigation conducted an assessment to compare 5 error‐correction procedures that have been evaluated in the extant literature and are common in instructional practice for children with autism spectrum disorder (ASD). Results showed that the assessment identified efficacious and efficient error‐correction procedures for all participants, and 1 procedure was efficient for 4 of the 5 participants. To examine the social validity of error‐correction procedures, participants selected among efficacious and efficient interventions in a concurrent‐chains assessment. We discuss the results in relation to prior research on error‐correction procedures and current instructional practices for learners with ASD.     

Stability of daily preference across multiple individuals

Preference stability provides clues about the extent to which a clinician might be able to deliver a particular stimulus contingent on behavior as a reinforcer. Previous research has been somewhat mixed in terms of evidence for preference stability. Results of the current study are consistent with studies that have reported correlations between preference assessments, suggesting that preferences are relatively stable across time.     

Exploring inter-task transfer following a CO-OP approach with four children with DCD: A single subject multiple baseline design

IntroductionCognitive Orientation to daily Occupational Performance (CO-OP) approach has been shown to be effective for improving the performance of tasks worked on in therapy and the use of cognitive strategies. No study to date seems to have explored its effectiveness for improving performance of untrained tasks (inter-task transfer) in children with Developmental Coordination Disorder (DCD).ObjectiveThis study aimed to determine whether CO-OP leads to improved performance in an untrained task.MethodsA single-subject design with multiple baselines across skills was adopted, with three replications. Four children with DCD (7–12 years) received 10 sessions of CO-OP intervention where each child worked on three tasks during therapy sessions and a fourth task was identified, but not worked on, to verify inter-task transfer. Task performance was rated over four phases (baseline, intervention, post-intervention, follow-up) using the Performance Quality Rating Scale (PQRS-OD). Graphed data was statistically analyzed using a two or three standard deviation band method.ResultsSignificant improvement was obtained for 11 of 12 tasks worked on during therapy and for two of the four untrained tasks.ConclusionThese results indicate that the effectiveness of CO-OP to improve untrained tasks in children merit further exploration.     

Site preference and alloying effect of tungsten in the μ phase of Co7Mo6

The electronic structures of the μ phase of Co₇Mo₆ were investigated by means of first-principles calculation based on the density functional theory. The calculated equilibrium lattice parameters of Co₇Mo₆ are in good agreement with the experimental results. The results of calculation reveal that the addition of tungsten (W) promotes the stability of the μ phase of Co₇Mo₆ and W tends to participate in its formation. Through analysing the calculated electronic structure (partial density of states and charge density difference), it can be noted that a strong interaction exists due to d–d hybridization. Also, the majority of the atoms may contribute their valence electrons to the formation of metallic bonds in binary and ternary systems. Furthermore, the calculated results show that the doped W atom prefers to occupy the Co site in Co₇Mo₆ μ phase.     

Preference Structure Modelling for Multi-objective Decision Making: A Goal–Programming Approach

We propose a new approach for modelling preference structures in multi-objective decision-making (MODM) problems. The basic idea of the approach is to first develop PROMETHEE-influenced objective functions and then to use these to reformulate the problem as a distance-based goal–programming (GP) model. Three basic functional forms are proposed and explicit expressions are developed for them. Among other things, the expressions allow for the straightforward development of an interactive framework while keeping the information requirements from the decision maker (DM) at a minimum. An ‘automatic’ piecewise linear approximation scheme is proposed for solving the GP model. © 1997 by John Wiley & Sons, Ltd. J. Multi-Crit. Decis. Anal. 6 : 150–154 (1997) No. of Figures: 0. No. of Tables: 0. No. of References: 12.