This paper use grey forecasting model and unbiased grey forecasting model to test a series of slope data, and the results indicate that both methods are valid and the later is more accurate.

This paper use grey forecasting model and unbiased grey forecasting model to test a series of slope data, and the results indicate that both methods are valid and the later is more accurate.

The new test also sets the standard for providing fair, unbiased and objective scoring, building on ets's record and reputation as the world leader in all facets of educational assessment.