If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

# Identifying individuals, variables and categorical variables in a data set

The concept of variables in data sets comes to life through an exploration of categorical and quantitative variables. Using nutritional data from a coffee shop as an example, the lesson highlights how variables can represent diverse aspects of a data set, such as drink type, calorie count, sugar content, and caffeine amount.

## Want to join the conversation?

• what does categorical mean
• It means the data in the set can be sorted into categories, in this case hot drinks and cold drinks. The sugar content, on the other hand, is not categorical, because a drink could have infinite different amounts of sugar.
Hope this helps!
• Why isn't the type of drink classified as a variable?
• It's not a variable because it's not describing anything or numbering anything. For example, "Type" is a categorial variable because it describes the heat of the drinks. "Sugars" is a quantitative variable because it numbers the amount of sugar in the drinks.
• What are the prerequisites for the Statistics and Probability course?
• Algebra is a must for any Statistics and Probability course.

Whether or not calculus is also required depends on how deeply the course goes into probability theory. If the course covers topics such as probability density functions of continuous random variables, cumulative distribution functions of continuous random variables, moment generating functions, and/or maximum likelihood estimators, then calculus would be required.
• what is standard deviation?
• Standard deviation is a measurement of the spread of the data. If you have a high standard deviation, that means your data are far away from the mean, while if it is low it means they are closer.
Hope this helps!
• I'm interested in learning about stats and probability however I have never learned about it in class. I've covered other math classes like algebra, advanced functions, calculus and a bit of linear algebra. Would this course be good for someone wanting to learn stats for fun? Or should I do other courses prior? Thanks!
• I think this course would be excellent for someone wanting to learn stats for fun. It's modeled off AP Statistics, a class for high schoolers wanting to explore college level statistics. There is a course on Khan Academy called "Get ready for AP Statistics", but if you have experience with linear algebra I think you'll find it very easy. Perhaps you could try Khan Academy's "High school statistics" course, but I don't think you'd need to take other courses prior to this one. Happy learning!
• where can you find the "individuals" of set of data in a given table?
• An individual is what the data is describing. In a table like this, each individual is represented by one row. So in this case, the individuals would be the drinks. An example individual is cappuccino, which is a hot coffee that has 60 calories, 8 grams of sugar, and 75 milligrams of caffeine.
• I'm in seventh grade. Is this suitable for my grade level?
• I’m looking at this problem also from a machine learning perspective. In that sense wouldn’t we also include the column ‘drink name’ here also be counted as a categorical variable ? Please help me out here.
Thanks !
• Similar to how Sal explained in the video, the drink name would not be a categorical variable in the sense that the pursuing variables are all describing it; therefore, it is an individual. (Variables describe the individual)

Hope this helps!
• okay, so categorial is more like something that describes it, like in this example, if the coffee is hot or cold. and quantitative is more like the caloric intake, the actual amounts with numbers?