Using .eq() and .data() does not mod HTML

Using .eq() and .data() does not mod HTML

I am doing something like the following:

var set = $('div#this_one');
var next_sibs = set.nextAll();

for (var i = 0; i < sibs.length; ++i)
{
var item = sibs.eq(i); // get this item in the set.
var info = item.data(); // the the data for this item.
info.new_value = 42 + i; // modify the "field" in the data
}

When I look at the variables in FireBug, they are as expected; but when I look at the results in the HTML page the value retains its original value.

Thank you.