Last Updated on August 19, 2020 Calculating the average of a variable or a list of numbers is a common operation in machine learning. It is an operation you may use every day either directly, such as when summarizing data, or indirectly, such as a smaller step in a larger procedure when fitting a model. The average is a synonym for the mean, a number that represents the most likely value from a probability distribution. As such, there are multiple […]

Last Updated on August 19, 2020 Degrees of freedom is an important concept from statistics and engineering. It is often employed to summarize the number of values used in the calculation of a statistic, such as a sample statistic or in a statistical hypothesis test. In machine learning, the degrees of freedom may refer to the number of parameters in the model, such as the number of coefficients in a linear regression model or the number of weights in a […]

Last Updated on September 1, 2020 Machine learning models are chosen based on their mean performance, often calculated using k-fold cross-validation. The algorithm with the best mean performance is expected to be better than those algorithms with worse mean performance. But what if the difference in the mean performance is caused by a statistical fluke? The solution is to use a statistical hypothesis test to evaluate whether the difference in the mean performance between any two algorithms is real or […]