Before making any type of inferences about the population, you need to know more about the data. What is the average score? Are there any outliers? Learn more about these questions and more in the video below.
Once your data have been collected and described, you can now make inferences. According to Merriam-Webster, to infer means “to derive as a conclusion from facts or premises.” This means that our conclusions are based on facts, but they are not definitive. Remember that because we typically do not use data from an entire population, we can only infer through a sample. However, this relies on principles of probability (and thus, chance!).
One type of inference we can make is to see if the means of two groups are different from each other. To do this, we use z-scores and t-scores and then calculate a significance test on the difference of means. Watch the video below on the principles of inferential statistics through the lens of difference of means tests. Other types of statistical techniques are then discussed in more detail below.