If after optimization, your page’s content sounds natural to a human visitor, it will probably appear valid to a search engine spider. However, don’t forget that the bots are still machines, and they analyze specific aspects of your text. Mainly, you should pay attention to the following properties:

1. Weight, also known as Density: This is the percentage of your key phrases in a given area, such as a META tag, or a page.

2. Prominence: This refers to how close your keyword is to the beginning of the analyzed area.

3. Frequency: This is the absolute number of the times a certain keyword is repeated in an area or another. Unlike Density, Frequency does not depend on the total number of words in the text.

4. Proximity: This refers to the distance between parts of your key phrase. While it’s always better to use a complete phrase, sometimes the language structure doesn’t allow this to happen. You’ll still have to keep the words as close as they can be in this case.