Statistics, Data Science

Which Statistical Test to Use? Follow This Cheat Sheet

Get all the statistical tests clear in 3 minutes!

The Question to be Answered

Before we decide on which test to use, we need to be clear of what we want to solve. Is it:

• To validate whether the population mean is correct
• To compare the difference between 2 groups of data to see whether the difference is statistically significant
• To validate whether there’s a relationship between 2 categorical variables

Null and Alternative Hypothesis

Next, you will be deciding on the hypothesis based on your test objective. A null hypothesis (H0) proposes that no significant difference exists in a set of given observations, and an alternative hypothesis (H1) proposes otherwise.

For rejecting a null hypothesis, a test statistic is calculated. This test-statistic is then compared with a critical value. The critical values are the boundaries of the critical region.

• If the test statistic > critical value, the null hypothesis is rejected.
• If the test statistic ≤ critical value, the null hypothesis is accepted.

P-Value

Other than test statistic, P-value is another important result to look at. P-value is the level of marginal significance within a…