[4] Precise definitions vary,[5] but features often cited as characteristic of hard science include producing testable predictions, performing controlled experiments, relying on quantifiable data and mathematical models, a high degree of accuracy and objectivity, higher levels of consensus, faster progression of the field, greater explanatory success, cumulativeness, replicability, and generally applying a purer form of the scientific method.
[2][6][7][8][9][10][11][12] A closely related idea (originating in the nineteenth century with Auguste Comte) is that scientific disciplines can be arranged into a hierarchy of hard to soft on the basis of factors such as rigor, "development", and whether they are basic or applied.
The more "developed" hard sciences do not necessarily have a greater degree of consensus or selectivity in accepting new results.
[15] The metaphor has been criticised for unduly stigmatizing soft sciences, creating an unwarranted imbalance in the public perception, funding, and recognition of different fields.
This view was highly influential, and was intended to classify fields based on their degree of intellectual development and the complexity of their subject matter.
[5] In a 2010 article, Fanelli proposed that we expect more positive outcomes in "softer" sciences because there are fewer constraints on researcher bias.
They found that among research papers that tested a hypothesis, the frequency of positive results was predicted by the perceived hardness of the field.
[25] An editorial in Nature stated that social science findings are more likely to intersect with everyday experience and may be dismissed as "obvious or insignificant" as a result.