A method used by a human to check the logic of a computer program's algorithm to reduce the likelihood of errors occurring. This may be done on paper, using a diagram, or mentally trying a sample of typical inputs to see what the outputs would be. For example, to desk check a branching statement {IF age >65 THEN ‘retire’ ELSE ‘keep working’}, the values for age of 64, 65 and 66 could be tried to show that 64 and 65 would result in ‘keep working’ and 66 in ‘retire’ so that it could be decided if the statement worked as intended.