Pairing words with syntactic frames: syntax, semantics, and count-mass usage.

Two experiments examined English speakers' choices of count or mass compatible frames for nouns varying in imageability (concrete, abstract) and noun class (count, mass). Pairing preferences with equative (much/many) and non-equative (less/fewer) constructions were compared for groups of teenagers, young adults, and older adults. Deviations from normative usage were, for all ages, larger for count than for mass nouns, for the non-equative than for the equative construction, and for abstract count than for concrete count nouns. These results indicate that mass syntax is not a developmental default, support proposals that mass syntax is more flexible than count syntax, verify the non-prescriptive use of less with count nouns, and extend the interaction of syntax and semantics in noun classification to older ages, with older adults showing a reduced reliance on semantics. Knowledge of frame compatibility and knowledge of noun class are also shown to be largely independent.

Cutting effectiveness of carbide burs following multiple steam autoclaving cycles.

New carbide burs that are placed on a bur block can be subjected to multiple steam autoclaving cycles prior to their first use. The decision to discard a bur before or during cavity preparation is a subjective one based on operator expectations and experience. This study examined the durability of carbide burs after multiple autoclaving cycles by judging not only their initial sharpness but also their ability to maintain sharpness throughout a cavity preparation. Five experienced operators were given a set of No. 330 carbide burs that had been separated into five blind categories: those not autoclaved at all and those that had been autoclaved one, two, five, or 10 times. Each operator judged the cutting effectiveness of each bur by making an initial plunge cut through the enamel of a freshly extracted tooth. After the initial plunge cut, each operator used the same set of burs to complete an occlusal cavity preparation in molar models fabricated from composite restorative material. Each operator was asked to examine the burs for any visual deterioration and to rate the cutting ability of each bur. The burs were also examined for wear under a scanning electron microscope. Based on the results, this study concluded that up to 10 autoclaving cycles did not significantly affect the perception of either initial sharpness or the bur's effectiveness while completing the preparation.

Strategy selection and use during classification skill acquisition.

Two experiments examined 3 variables affecting accuracy, response time, and reports of strategy use in a binary classification skill task. In Experiment 1, higher rule cue salience, allowing faster rule application, produced higher aggregate rule use than lower rule cue salience. After participants were pretrained on the relevant classification rule, rule reports were high but generally declined across training trials; after participants were pretrained on an irrelevant rule, reports of the relevant rule increased across training trials. In Experiment 2, no rule pretraining produced a pattern of results like that obtained with irrelevant rule pretraining in Experiment 1. Presenting novel stimuli during training in Experiment 2 elevated aggregate rule reports relative to conditions where they were absent. Two participant subgroups were identified: those persisting in rule reports and those transitioning from rule to memory reports during training. The proportion of persistent rule users was higher after rule discovery than after relevant rule pretraining. Overall, the results indicate that differences among prior experiments can be reconciled. Further, they raise questions about the inevitability of memory-based automaticity in binary classification, favoring instead strategy choice based on the costs and benefits of a particular strategy and of a shift from one strategy to another.