According to ALSC, "The Robert F. Sibert Informational Book Medal is awarded annually to the author(s) and illustrator(s) of the most distinguished informational book published in English during the preceding year. The award is named in honor of Robert F. Sibert, the long-time President of Bound to Stay Bound Books, Inc. of Jacksonville, Illinois."
“Information books are defined as those written and illustrated to present, organize, and interpret documentable, factual material for children.” (Source of all Award information: ALSC Sibert Medal home page)
In order to qualify for the Robert F. Sibert Informational Book Award, the authors, author/illustrator, co-authors, or author and illustrator named on the title page must be citizens or residents of the United States, and the book must be an original work that was first published in the U.S. ALSC stresses, “The award is not presented for didactic intent or for popularity.”
To learn about recent Sibert Award winners, see the following articles:
The 2011 Robert F. Sibert Informational Book Medal Winner and Honor Books
The 2010 Robert F. Sibert Informational Book Medal Winner and Honor Books
The 2009 Robert F. Sibert Informational Book Medal Winner and Honor Books.
