Prediction Revisited

Essential Concepts

This book introduces a new approach to prediction, which requires a new vocabulary—not new words, but new interpretations of words that are commonly understood to have other meanings. Therefore, to facilitate a quicker understanding of what awaits you, we define some essential concepts as they are used throughout this book. And rather than follow the convention of presenting them alphabetically, we present them in a sequence that matches the progression of ideas as they unfold in the following pages.

• Observation: One element among many that are described by a common set of attributes, distributed across time or space, and which collectively provide guidance about an outcome that has yet to be revealed. Classical statistics often refers to an observation as a multivariate data point.
• Attribute: A recorded value that is used individually or alongside other attributes to describe an observation. In classical statistics, attributes are called independent variables.
• Outcome: A measurement of interest that is usually observed alongside other attributes, and which one wishes to predict. In classical statistics, outcomes are called dependent variables.
• Arithmetic average: A weighted summation of the values of attributes or outcomes that efficiently aggregates the information contained in a sample of observations. Depending on the context and the weights that are used, the result may be interpreted as a typical value or as a prediction of an unknown outcome.
• Spread: ...