In a study examining “demand” for food, responding of 8 adult male baboons (Papio c. anubis) was maintained under a fixed-ratio schedule of food reinforcement during daily 23-hr experimental sessions. Completion of the ratio requirement resulted in the delivery of one, five, or 10 1-g food pellets. Supplemental feeding was limited to fruit and a dog biscuit daily. Responding increased as “cost” was increased across a wide range of fixed-ratio values before reaching a maximum and then decreasing. Increasing the number of food pellets per delivery decreased total responding and the number of reinforcements per day. A unit-price analysis, in which intake was converted to grams per day and fixed-ratio values were converted to responses per gram, yielded demand functions that overlapped at lower unit prices. Under one or more multiple-pellet conditions, however, intake decreased more quickly than under the one-pellet condition as the fixed-ratio value was increased in all but 1 baboon. This indicates that even when using unit-price conversions, there was variability in total intake. Although unit-price conversions yielded intake data that were more consistent across conditions, conditions differed in response topography even at the same unit prices: Under the multiple-pellet conditions there were longer pauses in responding, running response rate was slower, and the first eating bout (i.e., “meal”) of the session was smaller than under the one-pellet condition. These findings (a) support the heuristic value of a unit-price analysis for studying responding for and consumption of commodities that have similar attributes, and (b) indicate that different response topographies may result in similar intakes of a commodity. 相似文献
Although it is common in community psychology research to have data at both the community, or cluster, and individual level,
the analysis of such clustered data often presents difficulties for many researchers. Since the individuals within the cluster
cannot be assumed to be independent, the use of many traditional statistical techniques that assumes independence of observations
is problematic. Further, there is often interest in assessing the degree of dependence in the data resulting from the clustering
of individuals within communities. In this paper, a random-effects regression model is described for analysis of clustered
data. Unlike ordinary regression analysis of clustered data, random-effects regression models do not assume that each observation
is independent, but do assume data within clusters are dependent to some degree. The degree of this dependency is estimated
along with estimates of the usual model parameters, thus adjusting these effects for the dependency resulting from the clustering
of the data. Models are described for both continuous and dichotomous outcome variables, and available statistical software
for these models is discussed. An analysis of a data set where individuals are clustered within firms is used to illustrate
fetatures of random-effects regression analysis, relative to both individual-level analysis which ignores the clustering of
the data, and cluster-level analysis which aggregates the individual data.
Preparation of this article was supported by National Heart, Lung, and Blood Institute Grant R18 HL42987-01A1, National Institutes
of Mental Health Grant MH44826-01A2, and University of Illinois at Chicago Prevention Research Center Developmental Project
CDC Grant R48/CCR505025. 相似文献
The concepts of behavioral economics have proven useful for understanding the environmental control of overall levels of responding for a variety of commodities, including reinforcement by drug self-administration. These general concepts are summarized for application to the analysis of drug-reinforced behavior and proposed as the basis for future applications. This behavioral agenda includes the assessment of abuse liability, the assay of drug-reinforcer interactions, the design of drug abuse interventions, and the formulation of drug abuse public policy. These separate domains of investigation are described as part of an overall strategy for designing model projects to control drug use and testing public policy initiatives. 相似文献
Previous designs for online calibration have only considered examinees’ responses to items. However, the use of response time, a useful metric that can easily be collected by a computer, has not yet been embedded in calibration designs. In this article we utilize response time to optimize the assignment of new items online, and accordingly propose two new adaptive designs. These are the D-optimal per expectation time unit design (D-ET) and the D-optimal per time unit design (D-T). The former method uses the conditional maximum likelihood estimation (CMLE) method to estimate the expected response times, while the latter employs the nonparametric k-nearest-neighbour method to predict the response times. Simulations were conducted to compare the two new designs with the D-optimal online calibration design (D design) in the context of continuous online calibration. In addition, a preliminary study was carried out to evaluate the performance of CMLE prior to its application in D-ET. The results showed that, compared to the D design, the D-ET and D-T designs saved response time and accrued larger calibration information per time unit, without sacrificing item calibration precision. 相似文献
Objective: This study explored the utility of using behaviour change taxonomies and checklists to systematically assess the content and delivery of behavioural support for physical activity delivered through an established exercise-referral scheme.
Design: An observation study was conducted whereby 22% of initial consultations were observed and audio-recorded, using quota sampling stratified by exercise-referral advisor.
Main outcome measures: Content was independently coded by two researchers, to assess; (i) completeness in delivering the programme protocol, (ii) behaviour change techniques delivered (defined using the CALO-RE taxonomy) and (iii) delivery style according to the Behaviour Change Counselling Index (BECCI).
Results: Protocol completeness was 63.6% (range 35.6–74.6%). The behaviour change techniques delivered most consistently were ‘providing information about where and when to perform the behavior’ (86%) and ‘setting outcome goals’ (82%). Other evidence-based techniques such as self-monitoring were infrequently observed. Variation in BECCI scores indicated that advisors could, but did not consistently, provide a client-centred service.
Conclusion: This study highlights how theoretically informed taxonomies can be useful in evaluating service delivery within applied practice, providing a meaningful way of assessing the completeness of protocol delivery relative to evidence. The provision of feedback to practitioners based on such objective criteria also facilitated positive academic-practitioner communication. 相似文献
Up to 15% of parents have an infant who will spend time in a neonatal intensive care unit (NICU). After discharge, parents may care for a medically fragile infant and worry about their development. The current study examined how infant illness severity is associated with family adjustment. Participants included parents with infants who had been discharged from the NICU 6 months to 3 years prior to study participation (N = 199). Via a Qualtrics online survey, parents reported their infants’ medical history, parenting stress, family burden, couple functioning, and access to resources. Multivariable regression analyses revealed that more severe infant medical issues during hospitalization (e.g., longer length of stay and more medical devices) were associated with greater family burden, but not stress or couple functioning. Infant health issues following hospitalization (i.e., medical diagnosis and more medical specialists) were associated with greater stress, poorer couple functioning, and greater family burden. Less time for parents was associated with increased stress and poorer couple functioning. Surprisingly, parents of infants who were rehospitalized reported less stress and better couple functioning, but greater family burden. Family-focused interventions that incorporate psychoeducation about provider−patient communication, partner support, and self-care may be effective to prevent negative psychosocial sequelae among families. 相似文献
By around the age of 5½, many children in the United States judge that numbers never end, and that it is always possible to add 1 to a set. These same children also generally perform well when asked to label the quantity of a set after one object is added (e.g., judging that a set labeled “five” should now be “six”). These findings suggest that children have implicit knowledge of the “successor function”: Every natural number, n, has a successor, n + 1. Here, we explored how children discover this recursive function, and whether it might be related to discovering productive morphological rules that govern language-specific counting routines (e.g., the rules in English that represent base-10 structure). We tested 4- and 5-year-old children’s knowledge of counting with three tasks, which we then related to (a) children’s belief that 1 can always be added to any number (the successor function) and (b) their belief that numbers never end (infinity). Children who exhibited knowledge of a productive counting rule were significantly more likely to believe that numbers are infinite (i.e., there is no largest number), though such counting knowledge was not directly linked to knowledge of the successor function, per se. Also, our findings suggest that children as young as 4 years of age are able to implement rules defined over their verbal count list to generate number words beyond their spontaneous counting range, an insight which may support reasoning over their acquired verbal count sequence to infer that numbers never end. 相似文献
Agency statistics in the UK and North America reveal that fewer men than women attend counselling, at a ratio of about 1:2. This study investigated men's experience of considering counselling, with the aim of gaining further understanding of factors that might contribute to the existing gender discrepancy in utilisation of counselling. Following responses by 47 men to written questionnaires, 10 men who had considered and ultimately attended counselling were interviewed, and a grounded theory method of analysis was used to generate and analyse the participants' experiences. Three interconnected categories emerged: societal perceptions of counselling and gender roles; change of experience over time; and knowledge — ‘knowing’ and ‘not knowing’ the protocols of counselling. The implications of these findings are discussed. It is recommended that prospective male clients should be provided with information about the counselling process, and that there needs to be increased awareness by counsellors and referring agents of male gender issues. 相似文献
Although not generally regarded as a significant area of inquiry, the condensation of argumentative structures and the presence of `miniaturized' yet self-sufficient arguments in stand-alone, sub-discursive linguistic units, especially those below the level of a compound sentence, deserve a close look. Built skillfully into key words, catchy phrases, subtly appealing tropes, etc., these condensed arguments are often instrumental in accounting for the way some small linguistic units work magic on the audience. Taking such mini structures seriously holds two promises for argumentation studies: a widened scope of investigation and a unique contribution to the understanding of how rhetorical effects are being produced at the sub-syntactic or lexical level. 相似文献
在新生儿重症监护病房(neonatal intensive care unit,NICU)中接受治疗的危重新生儿约90%结果良好,而这些患儿的父母100%都在此过程中遭受不同程度的心理创伤.患儿父母及其家人应被充分告知患儿的病情、治疗方案及可能的预后,这是他们拥有的知情权.在临床工作中,怎样运用良好的信息交流技巧让患儿父母充分理解病情、配合治疗又不过分紧张这对患儿的康复比对患儿实施具体的诊疗方案更重要.从患儿父母、医护人员、人文关怀的角度探讨NICU医护人员与患儿父母之间信息交流的技巧. 相似文献