On a need-to-know basis: Young children distinguish conventional and privileged information

Young children are biased to treat new information communicated to them as conventional, shareable, and known by others in their community. However, some information is privileged in the sense that is not intended to be shared with or known by all. The current study compared judgements regarding sharing conventional versus privileged information. Seventy-four 3- to 5-year-olds and adults responded to vignettes in which a protagonist had to decide whether to share conventional (an object name) or privileged information (surprise). Consistent with our hypothesis, there was no developmental change in sharing judgements for conventional information but a clear decrease with age for sharing privileged information. Nonetheless, even 3-year-olds were more likely to judge that conventional information should be shared more than privileged information, though this difference increased with age. While children overall treat information as shareable, there is an emerging ability to distinguish how conventional versus privileged information should be shared.

More than just accent? The role of dialect words in children's language-based social judgments

Recent research suggests that young children are capable of distinguishing between phonetically dissimilar spoken accents yet have difficulty in distinguishing between phonetically similar accents. The current studies aimed to determine whether the presence of dialect-specific vocabulary enhances young children's ability to categorize speakers. In Study 1, 4- to 7-year-old children performed tasks in which they matched speakers based on the dialect-specific vocabulary the speakers used. Participants were successful in matching speakers based on vocabulary at a rate significantly greater than chance. In Study 2, participants performed a task in which they inferred a speaker's future dialect-specific vocabulary use based on the speaker's previous vocabulary use. Participants were able to infer a speaker's vocabulary use at a rate significantly greater than chance, and participants also showed social preference for and selective trust of speakers who used the participants' native dialect vocabulary over those who used a non-native dialect vocabulary. These interesting results suggest that when accent differences are too subtle for children to categorize speakers, dialect-specific vocabulary may enhance young children's ability to categorize a speaker. The results of preference and selective trust questions also suggest that children as young as 4 years use their knowledge of a speaker's vocabulary to guide their preferred social interactions, choosing to interact with others who speak similarly to them.

A New Look at Children's Private Speech: The Effects of Age, Task Difficulty, and Parent Presence

The present study re-evaluated several hypotheses concerning the selfregulatory nature of children's private speech. It was hypothesised that if children's private speech is self-regulatory, it should differ systematically as a function of child's age, task difficulty, and the presence of another in a task situation, and it should be positively related to task performance. Twenty-four children at each of three age levels (2, 31/2, and 5 years) were videotaped while working alone and with a parent on different sets of 3 puzzles that varied in difficulty. Children's speech was recorded and coded as private or social. The proportion of total speech coded as private increased slightly with age and was curvilinearly related to puzzle difficulty, with the most private speech observed on moderately difficult puzzles. In addition, private speech was positively related to task performance, especially on medium and difficult tasks. These results are consistent with the view that private speech is self-regulatory. Parental presence had no effect on the percentage of private speech. These results suggest that parents' behaviour during joint problem-solving probably should not be taken to be strictly regulatory.

Two-year-olds differentially disambiguate novel words and facts

When presented with a pair of objects, one familiar and one unfamiliar, and asked to select the referent of a novel word, children reliably demonstrate the disambiguation effect and select the unfamiliar object. The current study investigated two competing word learning accounts of this effect: a pragmatic account and a word learning principles account. Two-, three- and four-year-olds were presented with four disambiguation conditions, a word/word, a word/fact, a fact/word and a fact/fact condition. A pragmatic account predicted disambiguation in all four conditions while a word learning principles account predicted disambiguation in the word/word and fact/word conditions. Results indicated that children disambiguated in word/word and fact/word conditions and two-year-olds disambiguated at above chance levels in the word/word condition but at BELOW chance levels in the fact/fact condition. Because disambiguation varied both as a function of age and condition these findings are presented as challenges to a pragmatic account of the disambiguation effect.

Beyond fast mapping: young children's extensions of novel words and novel facts

L. Markson and P. Bloom (1997) concluded that there was evidence against a dedicated system for word learning on the basis of their finding that children remembered a novel word and a novel fact equally well. However, a word-learning system involves more than recognition memory; it must also provide a means to guide the extension of words to additional exemplars, and words and facts may differ with regard to extendibility. Two studies are reported in which 2-4-year-old children learned novel words and novel facts for unfamiliar objects and then were asked to extend the words and facts to additional exemplars of the training objects. In both studies, children extended the novel word to significantly more category members than they extended the novel fact. The results show that by 2 years of age, children honor the necessary extendibility of novel count nouns but are uncertain about the extendibility of arbitrary facts.

Angular asymmetries of the human face

PURPOSE

The determination of an acceptable occlusal plane is essential for the development of esthetic prosthodontic restorations. However, since most faces are not symmetric, a method was developed for measuring facial angular asymmetry, i.e., the divergence from the vertical or horizontal of the line joining the midpoint of the intercanthal line and the philtrum of the lip, the interpupillary line, the intermeatal line, the lip commissure line, and the intercuspid line.

MATERIALS AND METHODS

Standardized frontal images (mouth closed, smiling, and biting on a wooden spatula) of 100 subjects were taken using a digital camera. These images were downloaded into a computer, and the angles between the various facial lines and the horizontal were measured. The subjects were grouped by sex, age, and history of trauma and orthodontic treatment.

RESULTS

No statistically significant differences were found between the mean values for each group.

CONCLUSION

Asymmetry of the face can be measured using digital camera imaging and computer analysis. A range of facial asymmetries that can influence the choice of occlusal plane during prosthodontic treatment exists. Thus, the use of an occlusal plane parallel to the ala tragus and interpupillary lines, as often advocated by prosthodontists, may result in less than ideal esthetics in the final restoration.

Morphological cues to verb meaning: verb inflections and the initial mapping of verb meanings

The present studies investigated children's use of verb inflections to guide their initial mapping of verb meanings. Given that children initially apply the progressive -ing inflection to verbs denoting actions and the past -ed inflection to verbs denoting results of events, two studies were conducted to investigate whether children use these inflections during mapping of novel verb meanings. In both studies, subjects were taught novel verbs and were asked to extend those verbs to events in which the action or result differed from events used to teach the verbs. It was predicted that subjects would be less likely to extend verbs inflected with -ing to events with new actions and would be less likely to extend verbs inflected with -ed to events with new results. Eighteen three- and five-year-olds and 24 adults participated in Experiment 1 in a between-subjects design that produced weak effects for the youngest subjects tested. Experiment 2 tested 16 three-year-olds and 19 five-year-olds in a within-subjects design and produced the predicted effect for three-year-olds, but not for five-year-olds. The findings are discussed in terms of their implications for early verb learning and regarding the use of the bootstrapping construct in language acquisition research.

Aesthetic control in fixed prosthodontics

Leaving the aesthetic results of fixed prosthodontic treatment to chance, or to the judgment of a technician without guidance, leads to many surprises and disappointments. This paper describes techniques for planning the aesthetic outcome in the dental surgery, conveying the specifications to the dental technician and controlling the various aesthetic elements during construction of the restoration.

The development of verb concepts: children's use of verbs to label familiar and novel events

The importance of actions, results, and instruments in verb concepts was examined in four studies. Study 1 investigated how children label familiar events for which instrument, action, and result verbs were appropriate labels. In Study 2, subjects were taught novel verbs and were asked to use these verbs to label events in which the instrument, action, or result had been changed. Study 1 showed that 3-year-olds used action verbs more frequently than older children and adults, and that they preferred to use an action verb over a result verb when both verbs were appropriate labels. Instrument verbs were used most frequently as first responses to the events, and were most frequently used by older children and adults. In Study 2, subjects were least likely to use the novel verbs to label events in which the result had changed. This effect increased with age. Action changes had a moderate effect for all age groups, while instrument changes had the weakest effect. Studies 3 and 4 ruled out stimulus salience and a familiar word strategy as interpretations of these findings. The studies are discussed in terms of current theory and research on conceptual development, word-learning strategies, and the semantic organization of nouns and verbs.

Failure of maxillary canine retainers for fixed prostheses

A statistical survey of fixed prostheses with failed retainers, combined with information on the arch distribution of abutment teeth, supports the clinical impression that retainers on maxillary canines have a disproportionately high failure rate. The probable contributing factors are the form of the canine clinical crown, the distribution of occlusal force, and the paths of abutment tooth displacement. These factors are discussed and clinical techniques for countering their adverse effects are described.

An esthetic control system for fixed and removable prosthodontics

A set of devices and techniques has been developed to convey to the dental laboratory technician the information that is essential for the correct placement and alignment of anterior crowns, pontics, or denture teeth. The system brings a measure of accuracy and control to the esthetic aspect of prosthodontics that is taken for granted in other procedures.

The design of multiple pontics

The "fused"multiple pontic design, previously described for the mandibular posterior segment, can be used in other parts of the mouth. The interpontic embrasures can be filled in the maxillary anterior segment using pink porcelain to improve the appearance of the fixed partial denture. The pink porcelain may also be used to solve the esthetic problems created by moderate ridge resorption and loss of the papilla between pontic and abutment. Patients with two or more missing maxillary incisors are frequently told that a fixed partial denture cannot achieve the same esthetic result as a removable prosthesis. However, patients can enjoy the advantages of fixed prosthodontics without sacrificing esthetics using the technique of pink porcelain application described.

The mandibular posterior fixed partial denture

Absence of a mandibular posterior tooth, particularly the first molar, is the basic common denominator in a wide range of dental disorders. Despite their awareness of this fact, many dentists are deterred from the routine construction of mandibular posterior fixed partial dentures because of several technical difficulties. An attempt has been made to show how these difficulties may be overcome to give a predictable and satisfactory result.