Please note that this is a scanned copy of a paper originally published in 1986, so the text is not as clear as in documents created as pdf files. You may need to enlarge certain parts in order to read the subscripts in the equations. This Digest (in conjunction with Part 1, Digest 309) presents daylight prediction methods that can be used as a first stage in assessing the visual and energy impacts of window design and the effectiveness of daylight-linked lighting controls. Part 1 (available separately - see DG309) covers the calculation of sky component and externally-reflected component. This part (part 2) deals with the internally-reflected component and corrections (for glazing, maintenance, etc) to the total daylight factor, and the calculation of average daylight factor. 8 pages.