Spurious rigor is a way of presenting results with unrealistic precision to make them sound more certain than they really are. This occurs most often in advertising campaigns and Internet arguments. This works as a successful bullshiting method because it's implicit that the value cited is precise to the number of significant figures quoted, e.g., 7.5% implies a precision between 7.45% and 7.54%. This isn't necessarily the case, however.
It can also be a side-effect of playing fast and loose with the concept of statistical significance by stripping the context from a value. You can quote a value like 47.058%, and this might indeed be "technically correct", but it feels far less rigourous if you say "8 out of 17" instead. The more numbers after the decimal point that there are, the more sure you can be of where they pulled it from.
- "This mouthwash kills 47.6% of all bacteria!"
- "A recent poll reveals that fully 33.333% of all atheists believe in moral relativism!"