Chapter 5 Spending our data

Learning objectives:

• Use {rsample} to split data into training and testing sets.
• Identify cases where stratified sampling is useful.
• Understand the difference between rsample::initial_time_split() and rsample::initial_split().
• Understand the trade-offs between too little training data and too little testing data.
• Define a validation set of data.
• Explain why data should be split at the independent experimental unit level.