Category Archives: Research tools and methods

Does it matter that data are Normally distributed?

Hypothesis testing vs. Estimation Hypothesis tests require that populations are Normally distributed in order for the tests to be reliable. When samples are drawn from Normally distributed populations, the distributions of F or t statistics can be calculated for any given sample size, and the F or t statistic for a specific experiment can be obtained from the distribution. This

Read more

Statistics you are interested in: simple linear regression – part 1

We introduced simple linear regression in a previous series and learned how to perform it in R (1, 2). What is the theory behind simple linear regression? How is it used to understand relationships between variables? What is another way to perform it in Python? The hsb2.csv dataset (available here) contains demographic and academic test scores data from 200 students.

Read more

The Open Science Framework, Part 2: adding files and contributors

In the previous post we learned how to create a project folder and pre-register a study protocol on the Open Science Framework (OSF). The OSF also serves as a good data repository to store data, and users can add contributors (i.e. collaborators) to projects. How is this done? To add files to a project, navigate to the OSF website, sign

Read more

The Open Science Framework, Part 1: pre-registering a study protocol

Pre-registration of study protocols increases research transparency by providing a time-stamped record of experimental or analysis decisions before studies are conducted. Protocol pre-registration is now mandatory or strongly encouraged for clinical trials, and is increasingly encouraged for basic science and pre-clinical research (e.g. see the Transparency and Openness Promotion Guidelines). The Open Science Framework (OSF) is an open source software

Read more

What is an exact test? An example using Fisher’s Exact test

Suppose you conduct a study to compare an outcome between healthy people and people with stroke, but you want to check whether the proportion of men and women in each group are similar. The Fisher’s Exact test is often used to test differences in proportions between groups, similar to a Chi-Square test. But what is an exact test? This helpful

Read more
« Older Entries