What you posted matches my copy on p. 32, titled "Biga, Starter Dough".
When looking this recipe up I realized why I never used this book... bread recipes that only list ingredients (especially flour) in volumes (cups) and don't include weights are hard for me to work with. The weight of flour is so inconsistent (depends on the type of flour, the humidity, an what method was used for measuring the flour - dip and sweep, spoon into the cup, pack the flour it, etc.), that it's hard to figure out how a dough is supposed to turn out.
I did find a chart in the back of the book where they say a cup of flour weights 4 ounces (actually a cup of flour weighs between and & 5 ounces, but okay, I'll go by their chart). Are you familiar with Bakers' Percentages? It's a very useful way of determining what the consistency of a dough should be like and also for scaling recipes up and down.
So the total water for the biga recipe is 14 oz, and the total flour is 14 oz (3.5 cups at 4 oz flour per cup). That gives you what's called a "hydration" rate (percentage of water to flour) of 1:1, or 100%. What that's going to give you is a very thick batter-like mixture (not what I would call a dough). A "normal" bread dough hydration is about 66-70%. A "wet" dough is 60-66% hydration. The ABin5 recipe is a super-wet dough at 50 - 58% hydration (approximately, based on their instruction to measure using the "dip and sweep" method). So you can see that the biga recipe at 100% hydration would be more of a thick batter than an actual dough. It's odd to me that they refer to it as a "biga" - in traditional breadmaking, the term "biga" refers to a starter that's the consistency of bread dough (from 50% hydratiaon to about 78%), and a biga is traditionally used within 3 days. This seems to me to be more of a poolish (equal parts flour and water by weight) that a true biga...
Based on the quantities of ingredients given for the bread (3.25 cups water & 7 cups flour), the bread recipe also makes and extraordinarly wet dough but they say to knead it... and that it will be "slightly sticky" - but I'm suspicious as to how exactly this is supposed to turn out.
I have worked with firm Biga starters (but not this one) and like the technique very much - the use of a firm starter refrigerated for several days allows remarkable flavors to develop, as well as added stregth to the dough to help it rise. You get different flavors developed depending upon the consistency of the starter. A firm Biga starter is great for wet doughs like Ciabatta, strengthening the gluten network.
So... how did yours turn out?
I'll recomend this site to you if you want to experiment with Italian breads -
http://www.theartisan.net /
I corresponded with the site owners for a while. They are serious bread bakers and worked hard to develop the breads and other Italian recipes on their site, and could possibly contact them by email with questions. Plus there's a ton of really great bread-baking information there.