Another distinction that can be made is to just use casting for "IsA" and not for "makeLookLikeA". So if you know a string comes from a database but is actually an int in the unofficial schema, feel free to use a cast (although in this case c# wants you to use Convert anyway). The same would go for a float. But not for when you are just using the cast to truncate the float. This distinction also accounts for DownCasting and UpCasting -- the object was always 'IsA', but the type might have been generalized for a list.