What Is the Difference Between Hard and Soft Science?

The Science Council gives this definition of science:

"Science is the pursuit and application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence." 

The council goes on to describe the scientific method as being comprised of the following components:

• Objective observation
• Evidence
• Experiment
• Induction
• Repetition
• Critical analysis
• Verification and testing

In some cases, systematic observation using the scientific method is a relatively straightforward process that can be easily replicated by others. In other instances, objective observation and replication can be difficult, if not impossible. In general, those sciences that can easily make use of the scientific method as described above are termed "hard sciences," while those for which such observations are difficult are termed "soft sciences."

The Hard Sciences

Sciences that explore the workings of the natural world are usually called hard sciences, or natural sciences. They include:

• Physics
• Chemistry
• Biology
• Astronomy
• Geology
• Meteorology

Studies in these hard sciences involve experiments that are relatively easy to set up with controlled variables and in which it is easier to make objective measurements. Results of hard science experiments can be represented mathematically, and the same mathematical tools can be used consistently to measure and calculate outcomes.

For example, X quantity of Y mineral can be tested with Z chemical, with a mathematically describable outcome. The same quantity of mineral can be tested over and over again with the same chemical with precisely the same results. There should be no variation in outcome unless the materials used to experiment have changed (for example, the mineral sample or the chemical are impure).

The Soft Sciences

In general, the soft sciences deal with intangibles and relate to the study of human and animal behaviors, interactions, thoughts, and feelings. Soft sciences apply the scientific method to such intangibles, but because of the nature of living beings, it is almost impossible to recreate a soft science experiment with exactitude. Some examples of the soft sciences, sometimes referred to as the social sciences, are:

• Psychology
• Sociology
• Anthropology
• Archaeology (some aspects) 

Particularly in sciences dealing with people, it may be difficult to isolate all the variables that can influence an outcome. In some cases, controlling the variable may even alter the results!

Simply put, in soft science it is harder to devise an experiment.

For example, let's say that a researcher hypothesizes that girls are more likely than boys to experience bullying. The research team selects a cohort of girls and boys in a particular class in a particular school and follows their experience. They find that the boys are more likely to be bullied. Then, the same experiment is repeated using the same number of children and the same methodologies in a different school, and they find the opposite outcome. The reasons for the differences are complicated to determine: They could relate to the teacher, the individual students, the socioeconomics of the school and surrounding community, and so forth. 

Is Hard Hard and Soft Easy?

The terms hard science and soft science are used less often than they used to be, in part because the terminology is misunderstood and misleading. People perceive "hard" to mean more difficult, whereas, in truth, it may be much more challenging to devise and interpret an experiment in a so-called soft science than in a hard science.

The distinction between the two types of science is a matter of how rigorously a hypothesis can be stated, tested, and then accepted or rejected. As we have come to understand it today, the degree of difficulty is less related to the discipline than it is to the specific question at hand. So, one might say the terms hard science and soft science have become outdated.