Author Archives: Joanna Diong

Calculating sample size for a 2 independent sample t-test

Scientists often plan for studies by calculating how many subjects or units need to be tested in order to find an effect. That is, they plan for a study using statistical power according to principles of hypothesis testing. Sample size calculations are usually required in ethics applications and grant proposals to justify the study. We previously learned how to calculate

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Indirect evidence of reporting bias in a survey of medical research studies

Reporting bias (ie. bias arising when dissemination of research findings is influenced by the results) is thought to be common in biomedical and medical research. However, exactly how common it is has been difficult to quantify. Albarqouni and colleagues examined how commonly reporting bias occurs by examining the distribution of p values in medical research studies, and compared these distributions

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The Conversation: Seven deadly sins of statistical misintepretation, and how to avoid them

The Conversation recently published a nice piece by Louis and Chapman on common statistical misinterpretations and how they can be avoided. Here is summary of the main points: Problem Reason Solution 1. Assuming small differences are meaningful Most small differences are due to chance, not meaningful differences Ask for the margin of error (ie. half of the 95% CI): if

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Sharing computer code and programs in neuroscience

Many areas of neuroscience require computational techniques to process or analyse data. Some journals including the Nature family of journals and BioMed Central are encouraging investigators to share computer code and programs to improve scientific reproducibility, but these practices are not always adopted. For complex projects with multiple collaborators, it may be unclear what or how much can be shared.

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IPython magic commands

Jupyter notebooks are a scientific computing development platform that can run many different programming languages, including Python via the interactive Python interpreter IPython. The key advantage in a notebook environment is that code can be sectioned into cells for testing while retaining all the interactive features of IPython, including magic commands. IPython magics are a specialised set of commands hosted

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Scientific computing is important but mastering the skills takes time

Scientifically Sound was born out of the need to provide an online resource to conduct science that is reproducible and valid. This resource is in recognition of the fact that learning the digital skills to manage and analyse data reliably takes time and can be daunting. These concerns were echoed in the recent Nature article Scientific computing: Code alert. It

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