Measurement is an important means for obtaining information in research and production. Both the quality of products and the productivity of production highly depend on measurement. An important trend in the development of measurement is its merging with information technology. The requirements in high accuracy of measurement, on-line and dynamic measurements, measurements of complicated parameters and under complex conditions and intelligent measurements ask for the merging of measurements with information technology. This merging is carried out through the whole process. Modulation and demodulation, data sampling and reconstruction, signal merging, data compression, filtering, signal transformation, time series analysis, spectrum analysis, data fitting and modeling, pattern recognition, neural network, simulation and virtual measurement, error separation, error compensation, redundancy technique, decision making, intelligent techniques, etc. , are widely used in measurements. Some practical examples of this merging are given in the paper. The accuracy of coordinate measuring machines (CMMs) can be greatly enhanced by using error compensation technique. Modeling, error calibration and compensation software are three key techniques in error compensation of CMMs. Applications of redundancy technique in roundness and spindle error motion measurement, in large scale metrology are presented as well. Redundancy technique provides a powerful means in optimization of measurements, system self-calibration, error compensation, recovering the lost information and many other applications.