Mathematically aggregating experts' predictions of possible futures.

Structured protocols offer a transparent and systematic way to elicit and combine/aggregate, probabilistic predictions from multiple experts. These judgements can be aggregated behaviourally or mathematically to derive a final group prediction. Mathematical rules (e.g., weighted linear combinations of judgments) provide an objective approach to aggregation. The quality of this aggregation can be defined in terms of accuracy, calibration and informativeness. These measures can be used to compare different aggregation approaches and help decide on which aggregation produces the "best" final prediction. When experts' performance can be scored on similar questions ahead of time, these scores can be translated into performance-based weights, and a performance-based weighted aggregation can then be used. When this is not possible though, several other aggregation methods, informed by measurable proxies for good performance, can be formulated and compared. Here, we develop a suite of aggregation methods, informed by previous experience and the available literature. We differentially weight our experts' estimates by measures of reasoning, engagement, openness to changing their mind, informativeness, prior knowledge, and extremity, asymmetry or granularity of estimates. Next, we investigate the relative performance of these aggregation methods using three datasets. The main goal of this research is to explore how measures of knowledge and behaviour of individuals can be leveraged to produce a better performing combined group judgment. Although the accuracy, calibration, and informativeness of the majority of methods are very similar, a couple of the aggregation methods consistently distinguish themselves as among the best or worst. Moreover, the majority of methods outperform the usual benchmarks provided by the simple average or the median of estimates.

Counterfactual thinking and ascriptions of cause and preventability.

Research suggests that counterfactuals (i.e., thoughts of how things might have been different) play an important role in determining the perceived cause of a target outcome. Results from 3 scenario studies indicate that counterfactual content overlapped primarily with thoughts of how an outcome might have been prevented (preventability ascriptions) rather than with thoughts of how it might have been caused (causal ascriptions). Counterfactuals and preventability ascriptions focused mainly on controllable antecedents, whereas causal ascriptions focused mainly on antecedents that covaried with the target outcome over a focal set of instances. Contrary to current theorizing, causal ascriptions were unrelated to counterfactual content (Study 3). Results indicate that the primary criterion used to recruit causal ascriptions (covariation) differs from that used to recruit counterfactuals (controllability).

Should this child be removed from home? Hypothesis generation and information seeking as predictors of case decisions.

Two vital aspects of the investigative process in child abuse and neglect (CAN) cases are (a) generating as many plausible hypotheses as possible and (b) seeking out as much uncontaminated information as possible. Alternatively, unwarranted assumptions about the nature of CAN cases can impair investigative decision making. We examined whether the numbers of (a) unwarranted assumptions, (b) hypotheses generated, and (c) requests for additional information concerning a hypothetical reported case of CAN predicted level of agreement with a premature decision to remove a child from home among a group of CAN professionals. As expected, lower levels of agreement with the intervention were associated with (a) less unwarranted assumptions, (b) a greater number of hypotheses generated, and (c) more requests for information concerning the case. Compared with a group of undergraduates, a significantly greater percentage of CAN professionals requested information, and a significantly smaller percentage of professionals made unwarranted assumptions. Interestingly, however, no significant difference in mean level of agreement with the intervention was observed between professionals and undergraduates. Directions for future research are discussed.

Does sentential prosody help infants organize and remember speech information?

Theories that propose a mapping between prosodic and syntactic structures require that prosodic units in fluent speech be perceptually salient for infants. Although previous studies have demonstrated that infants are sensitive to prosodic markers of syntactic units, they do not show that prosodic information really has an impact on how infants encode the speech they hear. Two experiments were conducted to examine whether infants as young as 2 months old might actually use the prosody afforded by sentences to organize and remember spoken information. The results suggest that infants better remember the phonetic properties of (1) words that are prosodically linked together within a single clause as opposed to individual items in a list (Experiment 1); and (2) words that are prosodically linked within a single clausal unit as opposed to spanning two contiguous fragments (Experiment 2). Taken together, the evidence from both experiments suggests that the prosodic organization of speech into clausal units enhances infants' memory for spoken information. These findings are discussed with regard to their implications for theories of language acquisition.

When prosody fails to cue syntactic structure: 9-month-olds' sensitivity to phonological versus syntactic phrases.

According to prosodic bootstrapping accounts of syntax acquisition, language learners use the correlation between syntactic boundaries and prosodic changes (e.g., pausing, vowel lengthening, large increases or decreases in fundamental frequency) to cue the presence and arrangement of syntactic constituents. However, recent linguistic accounts suggest that prosody does not directly reflect syntactic structure but rather is governed by independent prosodic units such as phonological phrases. To examine the implications of this view for the prosodic bootstrapping hypothesis, infants in Experiment 1 were presented with sentences in which pauses were inserted either between the subject noun phrase (NP) and verb or after the verb. Half of the infants heard sentences with lexical NP subjects, in which prosodic structure is consistent with syntactic structure. The other half heard sentences with pronoun subjects, in which prosodic structure does not mirror syntactic structure. In a preferential listening paradigm, infants in the lexical NP condition listened longer to materials containing pauses between the subject and verb, the main syntactic constituents. However, in the pronoun NP condition, infants showed no difference in listening times for the two pause locations. To determine if other sentence types containing pronoun subjects potentially provide information about the syntactic constituency of these elements, infants in Experiment 2 heard yes-no questions with pronoun subjects, in which the prosodic structure reflects the constituency of the subject. Infants listened longer when pauses were inserted between the subject and verb than after the verb. Taken together, our results suggest that the prosodic information in an individual sentence is not always sufficient to assign a syntactic structure. Rather, learners must engage in active inferential processes, using cross-sentence comparisons and other types of information to arrive at the correct syntactic representation.

Two unusual strains of Candida arthritis.

Candida arthritis is an uncommon cause of infectious arthritis that may occur in seriously ill or immunosuppressed patients. This report describes two patients, one who developed Candida tropicalis arthritis and another patient who developed C. parapsilosis arthritis. One patient developed nephrogenic diabetes insipidus secondary to amphotericin B therapy and was successfully treated with intravenous miconazole. The other was unsuccessfully treated with both intraarticular and intravenous amphotericin B.