2. The hypothesis

2.1 Characteristics of a good hypothesis

A good hypothesis is based on a good question and should be straightforward, specific, and stated in advance.

Simple vs. composite

A simple hypothesis has one predictable variable and one judgment criterion: premature menopause is associated with a higher risk of fragility fractures.

A composite hypothesis has more than one predictable variable: premature menopause, age, and thinness are associated with a greater risk of fragility fracturesor has several judgment criteria: smoking is associated with a risk for cardiovascular disease and lung cancer.

A composite hypothesis cannot be tested with a simple statistical test.

Specific vs. vague

A specific hypothesis is unambiguous with regard to its components and its variables, and to the statistical test that is to be applied.