Measurements of defect density, photoconductivity, and dark conductivity are used to obtain information about the values of the electron capture cross sections of charged and neutral metastable dangling‐bond defects in high‐quality, undoped, hydrogenated amorphous silicon at room temperature. Sixty measurements, obtained in the process of optical degradation experiments as a function of time at four different temperatures, have been analyzed using photoconductivity models corresponding to either one or two types of discrete‐level, multivalent defects. A model with two types of defects is able to accurately describe both dark conductivity and photoconductivity results, and gives the following average values: an electron capture cross section of about 1×10−16cm2for neutral centers of both higher‐lying (density not increased by light) and lower‐lying (density increased by light) defects, of about 2×10−16cm2for positively charged higher‐lying defects, and of about 20×10−16cm2for positively charged lower‐lying defects. ©1996 American Institute of Physics.