text: Woodward's rules, named after Robert Burns Woodward and also known as Woodward–Fieser rules (for Louis Fieser) are several sets of empirically derived rules which attempt to predict the wavelength of the absorption maximum (λ) in an ultraviolet–visible spectrum of a given compound.  Inputs used in the calculation are the type of chromophores present, the auxochromes (substituents on the chromophores, and solvent. Examples are conjugated carbonyl compounds, conjugated dienes, and polyenes.