The article discusses a method for converting different types of tractors into standard reference tractors based on their power. Many farms have tractors with varying power and features, making it hard to analyze their efficiency. The researchers found that the power of a tractor determines its conversion factor to a standard reference tractor. This means even non-standard tractors can be represented as standard ones. For example, a John Deere 8430 tractor with 190 kW power can be converted to a factor of 2.6. This approach helps in assessing how to improve the use of farm machinery effectively.