Statistical power analysis provides the conventional approach to assess error rates when designing a research study. However, power analysis is flawed in that a narrow emphasis on statistical significance is placed as the primary focus of study …
The effect size (ES) is the magnitude of a study outcome or research finding, such as the strength of the relationship obtained between an independent variable and a dependent variable. Two types of ES indicators are sampled here: the difference-type …
Improved research practice is based on estimation of effect sizes rather than statistical significance. We discuss the challenging task of interpreting effect sizes in the research context, with particular attention to social psychological research. …
We outline the need to, and provide a guide on how to, conduct a meta-analysis on one’s own studies within a manuscript. Although conducting a “mini meta” within one’s manuscript has been argued for in the past, this practice is still relatively rare …
In this article, we present a model for determining how total research payoff depends on researchers’ choices of sample sizes, α levels, and other parameters of the research process. The model can be used to quantify various tradeoffs inherent in the …
A challenge when interpreting replications is determining whether the results of a replication “successfully” replicate the original study. Looking for consistency between two studies is challenging because individual studies are susceptible to many …
In a direct replication, the typical goal is to reproduce a prior experimental result with a new but comparable sample of participants in a high-powered replication study. Often in psychology, the research to be replicated involves a sample of …
Many psychology studies are statistically underpowered. In part, this may be because many researchers rely on intuition, rules of thumb, and prior practice (along with practical considerations) to determine the number of subjects to test. In Study 1, …
Methods for planning sample size (SS) for the standardized mean difference so that a narrow confidence interval (CI) can be obtained via the accuracy in parameter estimation (AIPE) approach are developed. One method plans SS so that the expected …