To measure the performance of a regression, the distance between the predicted outputs and the actual outputs, is a good model performance measure.
Rattle offers us a good way to see predicted values versus the actual value—the Predicted versus Observed plot. To test this plot, you need to create a regression model. You can download a sample dataset from the UCI Machine Learning Repository (http://archive.ics.uci.edu/ml; Irvine, CA: University of California, School of Information and Computer Science), or from Kaggle (http://www.kaggle.com/). On some websites, such as the UCI Machine Learning Repository, the datasets are classified by the task you want to perform with the dataset.
