Here's the answer:
Oil Vs. Extract
•Anise oil and anise extract can be used interchangeably in most recipes with some modifications to measurements. One part anise oil is equivalent to about four parts anise extract. Therefore, if a recipe calls for 1 tsp. of anise extract, use just 1/4 tsp. of anise oil.
Read more: Anise Oil Vs. Anise Extract Substitute | eHow.com
http://www.ehow.com/facts_5841324_an...#ixzz17Nwr7nuR
Hope that answers your question. :D