To Test or Not to Test?

Last summer, I spent some time thinking through the learning outcomes for each of my courses. With regard to my Introduction to Fiction class, I decided that tests were not helpful. It ultimately didn't matter if they retained the knowledge; what mattered was the thinking processes that are best developed through writing exercises and class discussion. I followed that principle this spring and was reminded of why so many professors give tests: without the test, there is a significant subset of students who will not read. And they will congratulate themselves for not reading.

The class is not entirely without comprehension assessments: there were 10 quizzes over the course of the semester. This subset of students did not do well on the quizzes, but since the quizzes only account for 5% of the grade, I suppose they thought they weren't important.

How shall I remedy this situation? Give a proper final exam instead of the creative monologue project (which I'm enjoying immensely and students are finding rewarding)? Count the quizzes for more? Assign more quizzes? Write letters to their parents? --Just joking, but sometimes I wish this were an option.