# How to Calculate a P-Value from a T-Test By Hand

One of the most common tests used in statistics is the t-test, which is often used to determine if a population mean is equal to some value.…

# What is Considered to Be a “Strong” Correlation?

In statistics, we’re often interested in understanding how two variables are related to each other. For example, we might want to know: What is the…

# Confidentiality vs Anonymity: What’s the Difference?

When researchers use surveys to collect data from individuals, they often say that the survey will be conducted confidentially or anonymously. These two terms are often confused by…

# Can a Z-Score Be Negative?

In statistics, a z-score tells us how many standard deviations away a value is from the mean. We use the following formula to calculate a z-score: z…

# Random Selection vs. Random Assignment

Random selection and random assignment are two techniques in statistics that are commonly used, but are commonly confused. Random selection refers to the process of randomly selecting…

# How to Conduct Grubbs’ Test in Excel

Grubbs’ Test is a statistical test that can be used to identify the presence of one outlier in a dataset. To use this test, the…

# Binomial Experiments: An Explanation + Examples

This tutorial defines a binomial experiment and provides several examples of experiments that are and are not considered to be binomial experiments.  Binomial Experiment: Definition A binomial…

# How to Calculate Margin of Error in Excel

Often in statistics, we’re interested in estimating a population parameter using a sample. For example, we might want to know the mean height of students at…

# Descriptive vs. Inferential Statistics: What’s the Difference?

There are two main branches in the field of statistics: descriptive statistics and inferential statistics. In this post, we’ll explain the difference between these two…

# A Simple Explanation of Internal Consistency

Internal consistency refers to how well a survey, questionnaire, or test actually measures what you want it to measure. The higher the internal consistency, the more…