Mackin’s Collection Development staff determine interest levels for titles on the website. Our highly trained staff have extensive experience reviewing books. All have degrees in library science, and many have education degrees as well. Information provided by publishers and review journals is combined with our staff’s professional opinions to evaluate samples of material provided by publishers. Topics considered when assigning interest levels are reading level, layout of the pages, size of the book, and number of pages. Interest level is expressed as a range to account for individual student tastes and preferences.