Category Archives: Biostatistics

Null Hypothesis Significance Testing: What you should know (Part 2)

In the previous article, we considered basic concepts about Null Hypotheses. This article will discuss Alternative Hypotheses.

Alternative Hypotheses

Since the primary purpose of Null Hypothesis Significance Testing (NHST) is to generate proof by contradiction, one must wonder what should be done if the null hypothesis is disproved/ falsified. This is where the alternative hypothesis comes into the picture- it provides an alternative to the null hypothesis. This is what the null hypothesis is tested against, so to speak. Put simply, if the null hypothesis is falsified, one accepts the alternative hypothesis as true.

If you recollect, the null hypothesis is what one wants to disprove. It follows then, that the alternative hypothesis is what one wants to prove. Therefore the alternative hypothesis is also called the Research Hypothesis, and is an explanation for why the null hypothesis was rejected.

Types of Alternative Hypotheses

  • Statistical Alternative
  • Substantive or Conceptual Alternative