could anyone give me a simple introduction to 'statistical weight'?

Statistics is the mathematical field that relates to probabilities of occurance. How likely is something to occur, or how likely is it that two observed behaviors are related, etc.. these types of questions.

Statistical weight refers to how closely one variable is related to another. A close relationship carries a high statistical weight, and a loose relationship carries a low statistical weight.

Statistics can establish possible relationships between variables, such as height, hair color and age size for example, but can also quantifiy how ikely those relationships are.

So, for example, suppose you measured height and hair color for 100 people. You might find that there is little correlation between hair color and height. So the relationship between the two would carry little statistical weight. However, you might find that height is very closely correlated with age, particulary between the ages of 0 to 12 years old. That relationship would carry a high statistical weight.

More generallyStatistics can establish possible relationships between variables, such as height and shoe size for example, but can also quantifiy how ikely those relationships are.

So, for example, suppose you measured height and shoe size for 100 people. If you plotted one agains the other on a graph, you would see a general trend (height increases with shoe size), but it wouldn't be perfect. There would be a few tall people with small feet, and vice versa.

Another example would be to explore correlations between obesity and different types of food being consumed. You may find that obesity is highly correlated with consumption of certain foods (most obese people eat food A, but few thin people eat it) and poorly correlated with other foods (both obese and thin people eat food B). The strength of these correlations represent the statistical weight.

Hope this helps,

-Guru