Statistics: suggestions, summaries and tips for understanding statistics

In short: Data

• Data is any collection of facts, statistics, or information that can be used for analysis or decision-making. It can be raw or processed, and it can be in the form of numbers, text, images, or sounds.

In short: Statistical samples

• A statistical sample is a small group of people or things that is used to represent a larger group. This is often done because it is not possible or practical to measure the entire group.
• If the sample is representative of the larger group, then the results of the analysis of the sample can be used to make inferences about the larger group.

Type-I and Type-II errors

When drawing conclusions, four scenarios are possible:

• Correct decision: the null hypothesis is incorrect, and the researcher rejects the null hypothesis.

• Correct decision: the null hypothesis is correct, and the researcher does not reject the null hypothesis.

• Type-I error: the null hypothesis is correct, but the researcher rejects the null hypothesis. The researcher falsely