The American Meteor Society collects only those rates made by individual observers reporting hourly rates. Certain statistical treatment permits use of group counts but the AMS is not set up to process such information. While group observing does have certain social and logistic advantages, in reporting we must insist that each person report only what he or she sees, regardless of whether co-observers see the same meteor or not. We tacitly assume that observers in such circumstances are NOT actively communicating and commenting to each other while observing. Meteor rates need to be corrected for less than perfect conditions, i.e. bright sky, clouds, haze, and ground obstruction.
Further correction is needed if the observer is plotting or recording data by hand or both.
The sky condition factor F is called 1.0 if stars to mag. 6.0 are visible at the zenith and if the sky is clear and free of obstruction. The factor F is lowered 0.1 for each 0.5-mag. If observing time was short of a full hour, then F is lowered 0.1 for each 6 minutes deficit. The minimum requirement for inclusion in past A.M.S. rate catalogs is F0.5.