nonni - 12:36 am on Apr 6, 2007 (gmt 0)

You don't need calculus to see how multiplication could be used to raise or lower scores without having 'negative' scores cancel each other out ... It involves reciprocal fractions. If a scale for evaluating the number of links (or quality of links, or spelling) goes to 100, anything between zero and .9999 will lower the total when multiplied out, 1 has no effect, and the bigger numbers increase things. In fact, compressed between zero and one is the entire magnitude of range between 1 and 100.

Such an approach would make it easy to grant relative importance to different factors - quality inbound links might be given a big maxium number (say 20), run-of-the mill links a lower number (5), key words something in between, etc, etc. If each factor is calculated seperately, it would be easy to change its importance over time.

With that type of math, penalties (anything under 1) can lower the product really fast. That might explain lots of pages going supplemental. Those types of functions are highly sensitive to the initial assumptions used to create penalties or maximum value, and it would take some tinkering to get things right.