The Similarity tab shows the results of the requirement similarity analysis for all requirements confirmed before analysis. Similar to the term similarity function in the Consistency tab, a Matching Strength slider at the top left of the tab lets you adjust how close should the requirements need to be in structure and terminology to be considered similar.
Setting this Matching Strength to 100% will only show identical requirement and helps you detect duplicates. Setting the strength to a lesser value will change the tolerance and allow more requirements to be considered similar.
It is useful to try different Strength settings as requirements that are very close to each other (say within 85% to 99%) may actually contradict each other, as is could just be a different quantity or possibly a negation of the other requirement.
The number of similar requirements found is also shown along with each requirement in the list. Expanding the requirement displays its similar requirements along with a percentage measure of how similar they are to each other.