The document discusses various concepts and methods of calculating productivity. It defines productivity as the ratio of output to input. Common inputs include labor hours, materials, and capital. Productivity can be calculated partially for individual inputs or totally considering all inputs. Common models include partial productivity, total productivity, total factor productivity, multi-factor productivity, and the APC model which includes a price recovery factor. The document also lists various ways to improve productivity such as through technology, employees, materials, processes, products, and tasks.