Popular understandings of economics often attempt to incorporate the methodology of natural sciences as the supposed key to economics. Some economic experts are of the view that the methods employed by the natural sciences, such as advanced mathematics, are important tools for the assessments of historical data to establish the state of an economy. It is also believed that the knowledge secured from the assessment of the empirical data is likely to be tentative since it is not possible to know the true nature of reality. Thinkers such as Milton Friedman held that the best approach to comprehend this elusive reality is to build a model that could generate accurate forecasts.

For instance, an economist forms a view that consumer outlays on goods and services are determined by disposable income and interest rates. Based on this view, he formulates a model, which is then validated by means of quantitative methods. An important test of the model is how well it fits with empirical data. The better the fit with the historical data, the higher the likelihood that the model is likely to be accepted as a useful tool for the assessment of the future consumer outlays.