The paper by Poskanzer and Voloshin discusses methods for analyzing anisotropic flow in relativistic nuclear collisions, emphasizing the use of Fourier expansion of azimuthal distributions. The authors present formulae relevant to this approach and explain how event multiplicity enters into the event plane resolution. They also discuss the role of non-flow correlations and provide a method for introducing flow into simulations. The study of anisotropic flow, particularly directed and elliptic flow, is crucial in understanding the evolution of nuclear collisions at high energies. The paper details the strategy for estimating the reaction plane, correcting Fourier coefficients for event plane resolution, and analyzing particle distributions with respect to the event plane. It also covers approximations for weak and strong flow conditions, event-by-event analysis of azimuthal distributions, and the contribution of non-flow correlations. Additionally, the authors provide a simple method to introduce anisotropic flow into Monte Carlo event generators. The discussion highlights the importance of higher harmonics, transverse radial and anisotropic flow, and pair-wise azimuthal correlations in the analysis of anisotropic flow.The paper by Poskanzer and Voloshin discusses methods for analyzing anisotropic flow in relativistic nuclear collisions, emphasizing the use of Fourier expansion of azimuthal distributions. The authors present formulae relevant to this approach and explain how event multiplicity enters into the event plane resolution. They also discuss the role of non-flow correlations and provide a method for introducing flow into simulations. The study of anisotropic flow, particularly directed and elliptic flow, is crucial in understanding the evolution of nuclear collisions at high energies. The paper details the strategy for estimating the reaction plane, correcting Fourier coefficients for event plane resolution, and analyzing particle distributions with respect to the event plane. It also covers approximations for weak and strong flow conditions, event-by-event analysis of azimuthal distributions, and the contribution of non-flow correlations. Additionally, the authors provide a simple method to introduce anisotropic flow into Monte Carlo event generators. The discussion highlights the importance of higher harmonics, transverse radial and anisotropic flow, and pair-wise azimuthal correlations in the analysis of anisotropic flow.