Sample size requirements for estimating pearson, kendall and spearman correlations

Interval estimates of the Pearson, Kendall tau-a and Spearman correlations are reviewed and an improved standard error for the Spearman correlation is proposed. The sample size required to yield a confidence interval having the desired width is examined. A two-stage approximation to the sample size requirement is shown to give accurate results.     

The distribution matters: two types of sample-size tasks

Different studies on how well people take sample size into account have found a wide range of solution rates. In a recent review, Sedlmeier and Gigerenzer (1997) suggested that a substantial part of the variation in results can be explained by the fact that experimenters have used two different types of sample-size tasks, one involving frequency distributions and the other sampling distributions. This suggestion rested on an analysis of studies that, with one exception, did not systematically manipulate type of distribution. In the research reported in this paper, well-known sample-size tasks were used to examine the hypothesis that frequency distribution versions of sample-size tasks yield higher solution rates than corresponding sampling distribution versions. In Study 1, a substantial difference between solution rates for the two types of task was found. Study 2 replicated this finding and ruled out an alternative explanation for it, namely, that the solution rate for sampling distribution tasks was lower because the information they contained was harder to extract than that in frequency distribution tasks. Finally, in Study 3 an attempt was made to reduce the gap between the solution rates for the two types of tasks by giving participants as many hints as possible for solving a sampling distribution task. Even with hints, the gap in performance remained. A new computational model of statistical reasoning specifies cognitive processes that might explain why people are better at solving frequency than sampling distribution tasks. Copyright© 1998 John Wiley & Sons, Ltd.     

Evaluation of publication bias in response interruption and redirection: A meta-analysis

Publication bias is the disproportionate representation of studies with large effects and statistically significant findings in the published research literature. If publication bias occurs in single-case research design studies on applied behavior-analytic (ABA) interventions, it can result in inflated estimates of ABA intervention effects. We conducted an empirical evaluation of publication bias on an evidence-based ABA intervention for children diagnosed with autism spectrum disorder, response interruption and redirection (RIRD). We determined effect size estimates for published and unpublished studies using 3 metrics, percentage of nonoverlapping data (PND), Hedges' g, and log response ratios (LRR). Omnibus effect size estimates across all 3 metrics were positive, supporting that RIRD is an effective treatment for reducing problem behavior maintained by nonsocial consequences. We observed larger PND for published compared to unpublished studies, small and nonsignificant differences in LRR for published compared to unpublished studies, and significant differences in Hedges' g for published compared to unpublished studies, with published studies showing slightly larger effect. We found little, if any, difference in methodological quality between published and unpublished studies. While RIRD appears to be an effective intervention for challenging behavior maintained by nonsocial consequences, our results reflect some degree of publication bias present in the RIRD research literature.     

Aggressiveness and dominance in captive cock red grouse

A method for measuring the aggressiveness of captive cock red grouse is described. A cock's aggressiveness varied according to season, type of cage and social environment. A method for ranking the dominance order of cocks in a group is also described. Dominance ranks remained stable for up to two years. Correlations between the aggressiveness of isolated cocks and their dominance ranks when in a group were positive but weak. Aggressiveness and dominance should be clearly distinguished. Both aggressiveness and dominance were related to the size of cock's combs, and implants of testosterone increased all three. In situations where a cock's aggressiveness changed, comb size changed in the same direction. The aggressive behaviour of captive cocks shows several major parallels with that of wild cocks.     

Kinship does not affect litter defence in pairs of communally nesting female house mice

Communal litter defence by sister and nonsister female mice can provide a valuable experimental paradigm to test whether females invest preferentially in kin. Since females within sister and nonsister pairs have different coefficients of relatedness with the young, the cumulative litter has more fitness value for related than for unrelated partners. Sister and nonsister paired females that gave birth simultaneously (n = 18), or at least within 7 days from each other (n = 12), were tested for maternal aggression on post partum day 7, or 10 days after the first delivery, respectively. Sister (n = 14) and nonsister pairs (n = 16) did not differ in cumulative values of post partum aggression or in the extent to which aggression was balanced within the pair. The aggressive behavior of each female was not correlated with her relative proportion of pups in the litter. Rather, the combined scores of aggression within the pairs were found to be positively correlated with the cumulative litter size. The analysis of mouse litter defence behavior shows that, under conditions of communal nesting, kinship does not seem to affect parental investment in the young significantly. Rather, the cumulative litter size could be used by paired females as a major indicator for parental investment allocation.     

加工流畅性对学习判断字体大小效应的影响

以自定步调学习时间和习得试验次数为加工流畅性指标,通过操纵不同字号的词对考察了加工流畅性对学习判断字体大小效应的影响。结果发现：（1）字体大小影响学习判断,但不影响回忆成绩;（2）不同字体大小的词对在加工流畅性（学习时间和学习次数）上存在差异,仅自定步调学习时间测量的加工流畅性对学习判断字体大小效应有贡献。这些结果说明学习判断的字体大小效应是一种元认知错觉现象,部分支持了加工流畅性假说。     

Microstructures and strengthening mechanisms in high-carbon titanium-microalloyed interstitial-free steels

We report the mechanical properties and microstructures of titanium-microalloyed interstitial-free (IF) steels with different carbon contents smelted and rolled in the laboratory. The results show an increase of yield strength and tensile strength with carbon content, which are enhanced with lower coiling temperature (CT). Microstructure analysis reveals that the ferrite grain size varies from 11 to 23?μm, while the average size of TiC as the main second-phase particle ranges from 10 to 35?nm. The sample with 80?ppm carbon and 853?K CT reaches a mechanical strength close to that of high-strength IF steels. The increase of yield strength is mainly attributed to both grain-refining and precipitation strengthening.     

Withdrawal of spatial overt attention following intentional forgetting: evidence from eye movements

Eye movements were measured to examine whether item-method directed forgetting involved a spatial overt attention shift. Experiment 1 showed that participants’ eyes were moved away from the study word following the forget and ignore cues, but not the remember cue. Experiment 2 revealed that the eyes were moved away from the area that covered by the study word even when the study word disappeared upon the presentation of the memory cue. Both the study word and memory cue were presented auditorily in Experiment 3. In all experiments, the to-be-remembered words were recalled better than both to-be-forgotten and to-be-ignored words. More importantly, mental effort, as indexed by the pupil size, increased following the remember, as compared with the forget and ignore cues. These findings are discussed in terms of controlling spatial overt attention after encoding to withdraw attention from irrelevant information and to allocate cognitive resources to relevant information for long-term retention.     

Dress fit and body image: A thematic analysis of women's accounts during and after trying on dresses

This study was designed to investigate women's experiences of dress fit and body image. Spontaneous speech of 20 women aged 18–45 years was audio-recorded while they tried on a number of dresses. They were also body-scanned and photographed in their chosen dress and discussed both the scan and the photograph in semi-structured interviews. Data were analysed using inductive thematic analysis and four key themes were found: the slim hourglass ideal, functional aspects of clothes fit, body confidence and clothes fit, and clothes dimensions and size coding. All themes and component sub-themes were ratified in follow-up sessions six months after the original interviews. It was concluded that these women had a complicated relationship with clothes fit and sizing and used well-fitting clothes to increase body confidence, cover perceived flaws, and to try to attain a slender hourglass look. Ideas for future directions for research in these areas are discussed.