sentences:  Over the next eighteen years, ISI created a variety of developmentally appropriate materials, or "content-based thinking skills," for schools based on research from student reading performance and different educational teaching models (Thinking Maps, Inc., 2011).In 1988, David Hyerle wrote Expand Your Thinking, which was the first resource where his Thinking Maps were published, and at that point, he began training educators to use his Thinking Maps (Thinking Maps, Inc., 2011).In 1994, test results indicated that "Thinking Maps significantly affect[ed] standardized and qualitative measures of student performance" (Thinking Maps Inc., 2011).