I'm learning the linear regression now. I used R to build linear model upon a set of train model and try to predict() data based on the test data.My question: I understand how train data gets collected. But what's with the test data? How did it get collected? Is the test data built, or is it collected, or is it predicted or what?PS: I'm learning data science by method of self-learning, so I lack the structural in my knowledge. I might know something on one place while lack the knowledge at another place. Please forgive and guide. Thanks. :)
How does the test data gets collected?
beginner;linear regression