Does the "Flipped Classroom" increase student understanding and proficiency? [Flipped Data Part 2 - Math Analysis Unit N]

After each assessment, I will be analyzing data from my 2011-2012 students in comparison with my 2010-2011 students.

 In 2010-2011, I did not "flip" my class.  All lessons were taught in class and all practice was done at home by students.  A very small amount of support videos were available to students near the end of the year, but were optional and only watched by a few students. (Math Analysis only; no videos available for Algebra 1).
In 2011-2012, I began trialing the flipped class in the first semester and fully flipped my class during the second semester.  This flipped classroom included all lesson instruction being done via video and most practice done in class.  Students were required to watch the lesson, write a summary, and ask a higher-order thinking question at home.  In class, students reviewed the lesson, answered their questions, and worked on practice.  Activities and methods were structured, but varied based on content and throughout the week to mix things up.
The only difference between the 2010-2011 school year was the flipped classroom.  All instruction, supplementary materials, quizzes, tests, practice assignments, online resources, teaching strategies, etc were identical. (Quizzes and tests had different questions, but same content and level of difficulty).
I am using a GoogleDocs Spreadsheet with formulas input to analyze my data.  I have looked back into my 2010-2011 gradebook to gather the information from all tests that year.   The only place that the data would be skewed is in the 2010-2011 class averages.  Students who failed the test but retook it had their score "excused" (erased from the average) and input in a different category.  Their original scores are no longer available.  Their original grades were input in the "F" category for this data analysis piece, but their scores do not factor into the class average, making the 2010-2011 averages seem slightly higher than they actually were.
Student demographics from both years were similar in terms of number of students, grade levels of students, and general class environment.

*This was the first Unit where students were allowed had full control over when they took Concept Quizzes.  They could use a "waiver" to get out of completing a full assignment if they could prove mastery on the concept by receiving a perfect score on the quiz (anything less than perfect required they complete the full assignment and retake the quiz the next day).  Students could move on to the next concept whenever they felt they had mastered the previous concept.  However, they still had a pace that they had to keep up with in terms of getting the videos watched and the practice problems completed by a certain date.

Read my weekly reflections (Math Analysis portion) for Week 4 and Week 5 to read more about what was going on during the weeks we studied this unit.

UNIT N RESULTS (Math Analysis - Unit Circle Trigonometry)

2010-2011: Class averages of 81.5% and 80.5%, for an overall average of 81.0%
2011-2012: Class averages of 87.1% and 88.8%, for an overall average of 87.9%


2010-2011: 69.1% (56 out of 81) of my students received A's or B's 
2011-2012: 83.3% (60 out of 72) of my students received A's or B's


2010-2011: 17.3% (14 out of 81) of my students received D's or F's
2011-2012: 6.9% (5 out of 72) of my students received D's or F's


These numbers show that the use of the Flipped Classroom seemed to influence student test scores in a positive way.  


There was 6.9% increase in the class average on the test.  


There was a 14.2% increase in students scoring proficient (80% or above), and a 19.8% increase in students receiving A's


There was a 10.3% decrease in students receiving failing (D/F) grades on the test.

Here is all of the data collected for this test via my GoogleDocs Spreadsheet:

See all data from this semester here