Effects of Population Distribution, Sample Size and Correlation Structure on Huberty’s Effect Size <em>R</em>

Effects of Population Distribution, Sample Size and Correlation Structure on Huberty’s Effect Size <em>R</em>

Effects of sample size on accuracy of species distribution models

Given increasing access to large amounts of biodiversity information, a powerful capability is that of modeling ecological niches and predicting geographic distributions. Because, sampling species’ distributions is costly, we explored sample size needs for accurate modeling for three predictive modeling methods via re-sampling of data for well-sampled species, and developed curves of model impr...

language learning strategies and vocabulary size of iranian efl learners

learning a second or foreign language requires the manipulation of four main skills, namely, listening, reading, speaking, and writing which lead to effective communication. it is obvious that vocabulary is an indispensible part of any communication, so without a vocabulary, no meaningful communication can take place and meaningful communication relies heavily on vocabulary. one fundamental fac...

Publication Bias in Psychology: A Diagnosis Based on the Correlation between Effect Size and Sample Size

BACKGROUND The p value obtained from a significance test provides no information about the magnitude or importance of the underlying phenomenon. Therefore, additional reporting of effect size is often recommended. Effect sizes are theoretically independent from sample size. Yet this may not hold true empirically: non-independence could indicate publication bias. METHODS We investigate whether...

Sample Size Planning 1 Running Head : Sample Size Planning Sample Size Planning with Effect Size Estimates

The use of effect size estimates in planning the sample size necessary for a future study can introduce substantial bias in the sample size planning process. For instance, the uncertainty associated with the effect size estimate may result in average statistical power that is substantially lower than the nominal power specified in the calculation. The present manuscript examines methods for inc...