also monogrammatic cross or tau-rho, is a ligature composed of a superposition of the Greek letters tau (Τ) and rho (Ρ). The symbol is of pre-Christian
Rho Tauri (ρTau, ρ Tauri) is a star in the constellation Taurus and a member of the Hyades star cluster. Rho Tauri is a white A-type main sequence dwarf
alpha (Cronbach's α {\displaystyle \alpha } ), also known as tau-equivalent reliability ( ρ T {\displaystyle \rho _{T}} ) or coefficient alpha (coefficient