Lumber is graded by application of regional grading standards, for example, the American Lumber Standards, which are based on one or more of the structural integrity, shape, dimensions, and appearance of a board. These grades take into account the sizes and locations of defects, together with the slopes of grains, shapes, and dimensions, to predict one or more of the load-bearing capacities and acceptable appearance of the boards. (These attributes of the boards, together with grade and trim symbols, are hereafter referred to collectively as “board attribute information.”)
Board grading designations represent board feature quality information produced after analysis of the boards, typically by an automatic grading system. The grading designations are developed from successive standard rule-based grades, each of which is expressed as a range of values. The standard rule-based grades represent the above-recited board structure and appearance metrics, and the ranges of values of successive standard rule-based grades represent different degrees of board feature qualities.
The growing number of automatic grading machines introduced to the forest products industry requires human check graders to inspect board lumber at increased speeds. The most common issue with either human or automatic grading of a board is lack of time allocated to make a decision. Some systems display grading system-produced board feature quality information on monitors near the inspection line. However, when a check grader has only a fraction of a second to read and process board grading designation information, flip the board, and again read and process board grading designation information, even the most skilled check graders lack an ability to perform a grade check task to the best of ability.
When presented with too much information, a check grader tends to make decisions that the check grader determines would afford the highest probability of success. If unable to consider all available data, the check grader may make the best decision with only part of the information, which most often results in an unacceptable assessment of board feature quality.