Narrowing In: Calculate Descriptive Statistics
Have a big picture idea of what your dataset includes? Alright, now let’s take a closer look at the variables you’re particularly interested in.
Descriptive statistics, sometimes referred to as summary statistics, give a quick and simple numerical description of your data. This includes mean, median, mode, minimum value, maximum value, and standard deviation. Descriptive statistics may help you identify things that you did not catch when you plotted your variables, such as outliers or skewed distributions.
You can calculate descriptive statistics for discrete or continuous quantitative variables, along with categorical variables.
Building Upon What You Know: Investigate Relationships
Much like in the game of Twenty Questions, it’s important to think critically about what information you’ve gotten so far, and how it all fits together. As you unearth more insights about your data through exploration, you’ll also want to consider the relationships between variables. Bivariate dimensionality is the relationship between two variables per subject, while multivariate dimensionality is a measurement made on many variables per subject.
It's also important to consider the degree of correlation between variables. If your data exploration leads you down the path of advanced analytics where you employ regression modeling, using variables that are too closely related may yield results that don’t reveal any new or real insights. Data exploration in the early stages can help you to identify variables that are truly independent, and to avoid multicollinearity.
Data exploration allows you to get familiar with your variables, form working hypotheses, and discover complex relationships early on in your analytics process. When exploring, think of yourself like a data detective playing Twenty Questions. Remember to start broad and then narrow in, and to always approach your data with an attitude of curiosity and intrigue. Data always has something to tell us, we just need eyes and ears that are alert to see and listen.