diff --git a/common/djangoapps/util/decorators.py b/common/djangoapps/util/decorators.py
new file mode 100644
index 0000000000..81ab747a3e
--- /dev/null
+++ b/common/djangoapps/util/decorators.py
@@ -0,0 +1,36 @@
+
+
+def lazyproperty(fn):
+    """
+    Use this decorator for lazy generation of properties that
+    are expensive to compute. From http://stackoverflow.com/a/3013910/86828
+    
+    
+    Example:
+    class Test(object):
+
+        @lazyproperty
+        def a(self):
+            print 'generating "a"'
+            return range(5)
+    
+    Interactive Session:
+    >>> t = Test()
+    >>> t.__dict__
+    {}
+    >>> t.a
+    generating "a"
+    [0, 1, 2, 3, 4]
+    >>> t.__dict__
+    {'_lazy_a': [0, 1, 2, 3, 4]}
+    >>> t.a
+    [0, 1, 2, 3, 4]
+    """
+    
+    attr_name = '_lazy_' + fn.__name__
+    @property
+    def _lazyprop(self):
+        if not hasattr(self, attr_name):
+            setattr(self, attr_name, fn(self))
+        return getattr(self, attr_name)
+    return _lazyprop
\ No newline at end of file
diff --git a/common/lib/xmodule/xmodule/capa_module.py b/common/lib/xmodule/xmodule/capa_module.py
index 7ce76def32..a384edf234 100644
--- a/common/lib/xmodule/xmodule/capa_module.py
+++ b/common/lib/xmodule/xmodule/capa_module.py
@@ -130,7 +130,7 @@ class CapaModule(XModule):
         if weight_string:
             self.weight = float(weight_string)
         else:
-            self.weight = 1
+            self.weight = None
 
         if self.rerandomize == 'never':
             seed = 1
diff --git a/common/lib/xmodule/xmodule/course_module.py b/common/lib/xmodule/xmodule/course_module.py
index acdc574220..7f4c204f45 100644
--- a/common/lib/xmodule/xmodule/course_module.py
+++ b/common/lib/xmodule/xmodule/course_module.py
@@ -3,6 +3,7 @@ import time
 import dateutil.parser
 import logging
 
+from util.decorators import lazyproperty
 from xmodule.graders import load_grading_policy
 from xmodule.modulestore import Location
 from xmodule.seq_module import SequenceDescriptor, SequenceModule
@@ -16,9 +17,6 @@ class CourseDescriptor(SequenceDescriptor):
 
     def __init__(self, system, definition=None, **kwargs):
         super(CourseDescriptor, self).__init__(system, definition, **kwargs)
-        
-        self._grader = None
-        self._grade_cutoffs = None
 
         msg = None
         try:
@@ -42,29 +40,79 @@ class CourseDescriptor(SequenceDescriptor):
     
     @property
     def grader(self):
-        self.__load_grading_policy()
-        return self._grader
+        return self.__grading_policy['GRADER']
     
     @property
     def grade_cutoffs(self):
-        self.__load_grading_policy()
-        return self._grade_cutoffs
+        return self.__grading_policy['GRADE_CUTOFFS']
+    
+    @lazyproperty
+    def __grading_policy(self):
+        policy_string = ""
+            
+        try:
+            with self.system.resources_fs.open("grading_policy.json") as grading_policy_file:
+                policy_string = grading_policy_file.read()
+        except (IOError, ResourceNotFoundError):
+            log.warning("Unable to load course settings file from grading_policy.json in course " + self.id)
+            
+        grading_policy = load_grading_policy(policy_string)
+            
+        return grading_policy
     
     
-    def __load_grading_policy(self):
-        if not self._grader or not self._grade_cutoffs:
-            policy_string = ""
+    @lazyproperty
+    def grading_context(self):
+        """
+        This returns a dictionary with keys necessary for quickly grading
+        a student. They are used by grades.grade()
+        
+        The grading context has two keys:    
+        graded_sections - This contains the sections that are graded, as
+            well as all possible children modules that can affect the
+            grading. This allows some sections to be skipped if the student
+            hasn't seen any part of it.
             
-            try:
-                with self.system.resources_fs.open("grading_policy.json") as grading_policy_file:
-                    policy_string = grading_policy_file.read()
-            except (IOError, ResourceNotFoundError):
-                log.warning("Unable to load course settings file from grading_policy.json in course " + self.id)
+            The format is a dictionary keyed by section-type. The values are
+            arrays of dictionaries containing
+                "section_descriptor" : The section descriptor
+                "xmoduledescriptors" : An array of xmoduledescriptors that 
+                    could possibly be in the section, for any student
+        
+        all_descriptors - This contains a list of all xmodules that can
+            effect grading a student. This is used to efficiently fetch
+            all the xmodule state for a StudentModuleCache without walking
+            the descriptor tree again.
             
-            grading_policy = load_grading_policy(policy_string)
-            
-            self._grader = grading_policy['GRADER']
-            self._grade_cutoffs = grading_policy['GRADE_CUTOFFS']
+        
+        """
+        
+        all_descriptors = []
+        graded_sections = {}
+        
+        def yield_descriptor_descendents(module_descriptor):
+            for child in module_descriptor.get_children():
+                yield child
+                for module_descriptor in yield_descriptor_descendents(child):
+                    yield module_descriptor
+        
+        for c in self.get_children():
+            sections = []
+            for s in c.get_children():
+                if s.metadata.get('graded', False):
+                    # TODO: Only include modules that have a score here
+                    xmoduledescriptors = [child for child in yield_descriptor_descendents(s)]
+                    
+                    section_description = { 'section_descriptor' : s, 'xmoduledescriptors' : xmoduledescriptors}
+                    
+                    section_format = s.metadata.get('format', "")
+                    graded_sections[ section_format ] = graded_sections.get( section_format, [] ) + [section_description]
+                
+                    all_descriptors.extend(xmoduledescriptors) 
+                    all_descriptors.append(s)
+        
+        return { 'graded_sections' : graded_sections,
+                 'all_descriptors' : all_descriptors,}
     
     
     @staticmethod
diff --git a/lms/djangoapps/certificates/views.py b/lms/djangoapps/certificates/views.py
index 6341133c52..472215ab5c 100644
--- a/lms/djangoapps/certificates/views.py
+++ b/lms/djangoapps/certificates/views.py
@@ -52,7 +52,7 @@ def certificate_request(request):
             return return_error(survey_response['error'])
 
         grade = None
-        student_gradesheet = grades.grade_sheet(request.user)
+        student_gradesheet = grades.grade(request.user, request, course)
         grade = student_gradesheet['grade']
 
         if not grade:
@@ -65,7 +65,7 @@ def certificate_request(request):
     else:
         #This is not a POST, we should render the page with the form
 
-        grade_sheet = grades.grade_sheet(request.user)
+        student_gradesheet = grades.grade(request.user, request, course)
         certificate_state = certificate_state_for_student(request.user, grade_sheet['grade'])
 
         if certificate_state['state'] != "requestable":
diff --git a/lms/djangoapps/courseware/grades.py b/lms/djangoapps/courseware/grades.py
index 6e7a0ce102..925b8429c6 100644
--- a/lms/djangoapps/courseware/grades.py
+++ b/lms/djangoapps/courseware/grades.py
@@ -3,26 +3,135 @@ import logging
 
 from django.conf import settings
 
+from models import StudentModuleCache
+from module_render import get_module, get_instance_module
 from xmodule import graders
 from xmodule.graders import Score
 from models import StudentModule
 
-_log = logging.getLogger("mitx.courseware")
+log = logging.getLogger("mitx.courseware")
 
-
-def grade_sheet(student, course, grader, student_module_cache):
+def yield_module_descendents(module):
+    for child in module.get_display_items():
+        yield child
+        for module in yield_module_descendents(child):
+            yield module
+   
+def grade(student, request, course, student_module_cache=None):
     """
-    This pulls a summary of all problems in the course. It returns a dictionary
-    with two datastructures:
+    This grades a student as quickly as possible. It retuns the 
+    output from the course grader, augmented with the final letter
+    grade. The keys in the output are:
+    
+    - grade : A final letter grade.
+    - percent : The final percent for the class (rounded up).
+    - section_breakdown : A breakdown of each section that makes
+        up the grade. (For display)
+    - grade_breakdown : A breakdown of the major components that
+        make up the final grade. (For display)
+    
+    More information on the format is in the docstring for CourseGrader.
+    """
+    
+    grading_context = course.grading_context
+    
+    if student_module_cache == None:
+        student_module_cache = StudentModuleCache(student, grading_context['all_descriptors'])
+    
+    totaled_scores = {}
+    # This next complicated loop is just to collect the totaled_scores, which is
+    # passed to the grader
+    for section_format, sections in grading_context['graded_sections'].iteritems():
+        format_scores = []
+        for section in sections:
+            section_descriptor = section['section_descriptor']
+            section_name = section_descriptor.metadata.get('display_name')
+            
+            should_grade_section = False
+            # If we haven't seen a single problem in the section, we don't have to grade it at all! We can assume 0%
+            for moduledescriptor in section['xmoduledescriptors']:
+                if student_module_cache.lookup(moduledescriptor.category, moduledescriptor.location.url() ):
+                    should_grade_section = True
+                    break
+            
+            if should_grade_section:
+                scores = []
+                # TODO: We need the request to pass into here. If we could forgo that, our arguments
+                # would be simpler
+                section_module = get_module(student, request, section_descriptor.location, student_module_cache)
+                
+                # TODO: We may be able to speed this up by only getting a list of children IDs from section_module
+                # Then, we may not need to instatiate any problems if they are already in the database
+                for module in yield_module_descendents(section_module):                    
+                    (correct, total) = get_score(student, module, student_module_cache)
+                    if correct is None and total is None:
+                        continue
+                    
+                    if settings.GENERATE_PROFILE_SCORES:
+                        if total > 1:
+                            correct = random.randrange(max(total - 2, 1), total + 1)
+                        else:
+                            correct = total
+                    
+                    graded = module.metadata.get("graded", False)
+                    if not total > 0:
+                        #We simply cannot grade a problem that is 12/0, because we might need it as a percentage
+                        graded = False
+                    
+                    scores.append(Score(correct, total, graded, module.metadata.get('display_name')))
+                    
+                section_total, graded_total = graders.aggregate_scores(scores, section_name)
+            else:
+                section_total = Score(0.0, 1.0, False, section_name)
+                graded_total = Score(0.0, 1.0, True, section_name)
+                
+            #Add the graded total to totaled_scores
+            if graded_total.possible > 0:
+                format_scores.append(graded_total)
+            else:
+                log.exception("Unable to grade a section with a total possible score of zero. " + str(section_descriptor.id))
+        
+        totaled_scores[section_format] = format_scores
+    
+    grade_summary = course.grader.grade(totaled_scores)
+    
+    # We round the grade here, to make sure that the grade is an whole percentage and
+    # doesn't get displayed differently than it gets grades
+    grade_summary['percent'] = round(grade_summary['percent'] * 100 + 0.05) / 100
+    
+    letter_grade = grade_for_percentage(course.grade_cutoffs, grade_summary['percent'])
+    grade_summary['grade'] = letter_grade
+    
+    return grade_summary
 
-    - courseware_summary is a summary of all sections with problems in the
-    course. It is organized as an array of chapters, each containing an array of
-    sections, each containing an array of scores. This contains information for
-    graded and ungraded problems, and is good for displaying a course summary
-    with due dates, etc.
+def grade_for_percentage(grade_cutoffs, percentage):
+    """
+    Returns a letter grade 'A' 'B' 'C' or None.
+    
+    Arguments
+    - grade_cutoffs is a dictionary mapping a grade to the lowest
+        possible percentage to earn that grade.
+    - percentage is the final percent across all problems in a course
+    """
+    
+    letter_grade = None
+    for possible_grade in ['A', 'B', 'C']:
+        if percentage >= grade_cutoffs[possible_grade]:
+            letter_grade = possible_grade
+            break
+    
+    return letter_grade  
 
-    - grade_summary is the output from the course grader. More information on
-      the format is in the docstring for CourseGrader.
+def progress_summary(student, course, grader, student_module_cache):
+    """
+    This pulls a summary of all problems in the course.
+
+    Returns
+    - courseware_summary is a summary of all sections with problems in the course. 
+    It is organized as an array of chapters, each containing an array of sections, 
+    each containing an array of scores. This contains information for graded and 
+    ungraded problems, and is good for displaying a course summary with due dates, 
+    etc.
 
     Arguments:
         student: A User object for the student to grade
@@ -30,49 +139,24 @@ def grade_sheet(student, course, grader, student_module_cache):
         student_module_cache: A StudentModuleCache initialized with all
              instance_modules for the student
     """
-    totaled_scores = {}
     chapters = []
     for c in course.get_children():
         sections = []
         for s in c.get_children():
-            def yield_descendents(module):
-                yield module
-                for child in module.get_display_items():
-                    for module in yield_descendents(child):
-                        yield module
-
             graded = s.metadata.get('graded', False)
             scores = []
-            for module in yield_descendents(s):
+            for module in yield_module_descendents(s):
                 (correct, total) = get_score(student, module, student_module_cache)
-
                 if correct is None and total is None:
                     continue
 
-                if settings.GENERATE_PROFILE_SCORES:
-                    if total > 1:
-                        correct = random.randrange(max(total - 2, 1), total + 1)
-                    else:
-                        correct = total
-
-                if not total > 0:
-                    #We simply cannot grade a problem that is 12/0, because we
-                    #might need it as a percentage
-                    graded = False
-
-                scores.append(Score(correct, total, graded,
-                                    module.metadata.get('display_name')))
+                scores.append(Score(correct, total, graded, 
+                    module.metadata.get('display_name')))
 
             section_total, graded_total = graders.aggregate_scores(
                 scores, s.metadata.get('display_name'))
 
-            #Add the graded total to totaled_scores
             format = s.metadata.get('format', "")
-            if format and graded_total.possible > 0:
-                format_scores = totaled_scores.get(format, [])
-                format_scores.append(graded_total)
-                totaled_scores[format] = format_scores
-
             sections.append({
                 'display_name': s.display_name,
                 'url_name': s.url_name,
@@ -88,13 +172,10 @@ def grade_sheet(student, course, grader, student_module_cache):
                          'url_name': c.url_name,
                          'sections': sections})
 
-    grade_summary = grader.grade(totaled_scores)
-
-    return {'courseware_summary': chapters,
-            'grade_summary': grade_summary}
+    return chapters
 
 
-def get_score(user, problem, cache):
+def get_score(user, problem, student_module_cache):
     """
     Return the score for a user on a problem
 
@@ -105,17 +186,18 @@ def get_score(user, problem, cache):
     correct = 0.0
 
     # If the ID is not in the cache, add the item
-    instance_module = cache.lookup(problem.category, problem.id)
-    if instance_module is None:
-        instance_module = StudentModule(module_type=problem.category,
-                                        module_state_key=problem.id,
-                                        student=user,
-                                        state=None,
-                                        grade=0,
-                                        max_grade=problem.max_score(),
-                                        done='i')
-        cache.append(instance_module)
-        instance_module.save()
+    instance_module = get_instance_module(user, problem, student_module_cache)
+    # instance_module = student_module_cache.lookup(problem.category, problem.id)
+    # if instance_module is None:
+    #     instance_module = StudentModule(module_type=problem.category,
+    #                                     module_state_key=problem.id,
+    #                                     student=user,
+    #                                     state=None,
+    #                                     grade=0,
+    #                                     max_grade=problem.max_score(),
+    #                                     done='i')
+    #     cache.append(instance_module)
+    #     instance_module.save()
 
     # If this problem is ungraded/ungradable, bail
     if instance_module.max_grade is None:
@@ -126,8 +208,11 @@ def get_score(user, problem, cache):
 
     if correct is not None and total is not None:
         #Now we re-weight the problem, if specified
-        weight = getattr(problem, 'weight', 1)
-        if weight != 1:
+        weight = getattr(problem, 'weight', None)
+        if weight is not None:
+            if total == 0:
+                log.exception("Cannot reweight a problem with zero weight. Problem: " + str(instance_module))
+                return (correct, total)
             correct = correct * weight / total
             total = weight
 
diff --git a/lms/djangoapps/courseware/management/commands/check_course.py b/lms/djangoapps/courseware/management/commands/check_course.py
index 6ccd6d5fe7..80f4b57983 100644
--- a/lms/djangoapps/courseware/management/commands/check_course.py
+++ b/lms/djangoapps/courseware/management/commands/check_course.py
@@ -78,8 +78,8 @@ class Command(BaseCommand):
 
         # TODO (cpennington): Get coursename in a legitimate way
         course_location = 'i4x://edx/6002xs12/course/6.002_Spring_2012'
-        student_module_cache = StudentModuleCache(sample_user, modulestore().get_item(course_location))
-        (course, _, _, _) = get_module(sample_user, None, course_location, student_module_cache)
+        student_module_cache = StudentModuleCache.cache_for_descriptor_descendents(sample_user, modulestore().get_item(course_location))
+        course = get_module(sample_user, None, course_location, student_module_cache)
 
         to_run = [
             #TODO (vshnayder) : make check_rendering work (use module_render.py),
diff --git a/lms/djangoapps/courseware/models.py b/lms/djangoapps/courseware/models.py
index 3b0ca7fdcf..631a750643 100644
--- a/lms/djangoapps/courseware/models.py
+++ b/lms/djangoapps/courseware/models.py
@@ -67,17 +67,19 @@ class StudentModuleCache(object):
     """
     A cache of StudentModules for a specific student
     """
-    def __init__(self, user, descriptor, depth=None):
+    def __init__(self, user, descriptors):
         '''
         Find any StudentModule objects that are needed by any child modules of the
-        supplied descriptor. Avoids making multiple queries to the database
-
-        descriptor: An XModuleDescriptor
-        depth is the number of levels of descendent modules to load StudentModules for, in addition to
-            the supplied descriptor. If depth is None, load all descendent StudentModules
+        supplied descriptor, or caches only the StudentModule objects specifically
+        for every descriptor in descriptors. Avoids making multiple queries to the 
+        database.
+        
+        Arguments
+        user: The user for which to fetch maching StudentModules
+        descriptors: An array of XModuleDescriptors.
         '''
         if user.is_authenticated():
-            module_ids = self._get_module_state_keys(descriptor, depth)
+            module_ids = self._get_module_state_keys(descriptors) 
 
             # This works around a limitation in sqlite3 on the number of parameters
             # that can be put into a single query
@@ -91,27 +93,52 @@ class StudentModuleCache(object):
 
         else:
             self.cache = []
-
-    def _get_module_state_keys(self, descriptor, depth):
-        '''
-        Get a list of the state_keys needed for StudentModules
-        required for this module descriptor
-
+    
+    
+    @classmethod
+    def cache_for_descriptor_descendents(cls, user, descriptor, depth=None, descriptor_filter=lambda descriptor: True):
+        """
         descriptor: An XModuleDescriptor
         depth is the number of levels of descendent modules to load StudentModules for, in addition to
             the supplied descriptor. If depth is None, load all descendent StudentModules
+        descriptor_filter is a function that accepts a descriptor and return wether the StudentModule 
+            should be cached
+        """
+        
+        def get_child_descriptors(descriptor, depth, descriptor_filter):
+            if descriptor_filter(descriptor):
+                descriptors = [descriptor]
+            else:
+                descriptors = []
+            
+            if depth is None or depth > 0:
+                new_depth = depth - 1 if depth is not None else depth
+
+                for child in descriptor.get_children():
+                    descriptors.extend(get_child_descriptors(child, new_depth, descriptor_filter))
+                
+            return descriptors
+        
+        
+        descriptors = get_child_descriptors(descriptor, depth, descriptor_filter)
+        
+        return StudentModuleCache(user, descriptors)    
+    
+    def _get_module_state_keys(self, descriptors):
         '''
-        keys = [descriptor.location.url()]
-
-        shared_state_key = getattr(descriptor, 'shared_state_key', None)
-        if shared_state_key is not None:
-            keys.append(shared_state_key)
-
-        if depth is None or depth > 0:
-            new_depth = depth - 1 if depth is not None else depth
-
-            for child in descriptor.get_children():
-                keys.extend(self._get_module_state_keys(child, new_depth))
+        Get a list of the state_keys needed for StudentModules
+        required for this module descriptor
+        
+        descriptor_filter is a function that accepts a descriptor and return wether the StudentModule 
+            should be cached
+        '''
+        keys = []
+        for descriptor in descriptors:
+            keys.append(descriptor.location.url())
+            
+            shared_state_key = getattr(descriptor, 'shared_state_key', None)
+            if shared_state_key is not None:
+                keys.append(shared_state_key)
 
         return keys
 
diff --git a/lms/djangoapps/courseware/module_render.py b/lms/djangoapps/courseware/module_render.py
index 5b4dc602e2..5e74e6f42e 100644
--- a/lms/djangoapps/courseware/module_render.py
+++ b/lms/djangoapps/courseware/module_render.py
@@ -50,9 +50,9 @@ def toc_for_course(user, request, course, active_chapter, active_section):
 
     chapters with name 'hidden' are skipped.
     '''
-
-    student_module_cache = StudentModuleCache(user, course, depth=2)
-    (course, _, _, _) = get_module(user, request, course.location, student_module_cache)
+    
+    student_module_cache = StudentModuleCache.cache_for_descriptor_descendents(user, course, depth=2)
+    course = get_module(user, request, course.location, student_module_cache)
 
     chapters = list()
     for chapter in course.get_display_items():
@@ -121,25 +121,26 @@ def get_module(user, request, location, student_module_cache, position=None):
       - position              : extra information from URL for user-specified
                                 position within module
 
-    Returns:
-      - a tuple (xmodule instance, instance_module, shared_module, module category).
-        instance_module is a StudentModule specific to this module for this student,
-            or None if this is an anonymous user
-        shared_module is a StudentModule specific to all modules with the same
-            'shared_state_key' attribute, or None if the module does not elect to
-            share state
+    Returns: xmodule instance
+    
     '''
     descriptor = modulestore().get_item(location)
-
-    instance_module = student_module_cache.lookup(descriptor.category,
-                                                  descriptor.location.url())
-
-    shared_state_key = getattr(descriptor, 'shared_state_key', None)
-    if shared_state_key is not None:
-        shared_module = student_module_cache.lookup(descriptor.category,
-                                                    shared_state_key)
+    
+    #TODO Only check the cache if this module can possibly have state
+    if user.is_authenticated():
+        instance_module = student_module_cache.lookup(descriptor.category,
+                                              descriptor.location.url())
+        
+        shared_state_key = getattr(descriptor, 'shared_state_key', None)
+        if shared_state_key is not None:
+            shared_module = student_module_cache.lookup(descriptor.category,
+                                                        shared_state_key)
+        else:
+            shared_module = None
     else:
+        instance_module = None
         shared_module = None
+        
 
     instance_state = instance_module.state if instance_module is not None else None
     shared_state = shared_module.state if shared_module is not None else None
@@ -163,9 +164,8 @@ def get_module(user, request, location, student_module_cache, position=None):
                'default_queuename': xqueue_default_queuename.replace(' ','_') }
 
     def _get_module(location):
-        (module, _, _, _) = get_module(user, request, location,
+        return get_module(user, request, location,
                                        student_module_cache, position)
-        return module
 
     # TODO (cpennington): When modules are shared between courses, the static
     # prefix is going to have to be specific to the module, not the directory
@@ -198,30 +198,59 @@ def get_module(user, request, location, student_module_cache, position=None):
         if has_staff_access_to_course(user, module.location.course):
             module.get_html = add_histogram(module.get_html, module)
 
-    # If StudentModule for this instance wasn't already in the database,
-    # and this isn't a guest user, create it.
+    return module
+
+def get_instance_module(user, module, student_module_cache):
+    """
+    Returns instance_module is a StudentModule specific to this module for this student,
+        or None if this is an anonymous user
+    """
     if user.is_authenticated():
+        instance_module = student_module_cache.lookup(module.category,
+                                              module.location.url())
+        
         if not instance_module:
             instance_module = StudentModule(
                 student=user,
-                module_type=descriptor.category,
+                module_type=module.category,
                 module_state_key=module.id,
                 state=module.get_instance_state(),
                 max_grade=module.max_score())
             instance_module.save()
-            # Add to cache. The caller and the system context have references
-            # to it, so the change persists past the return
             student_module_cache.append(instance_module)
-        if not shared_module and shared_state_key is not None:
-            shared_module = StudentModule(
-                student=user,
-                module_type=descriptor.category,
-                module_state_key=shared_state_key,
-                state=module.get_shared_state())
-            shared_module.save()
-            student_module_cache.append(shared_module)
-
-    return (module, instance_module, shared_module, descriptor.category)
+            
+        return instance_module
+    else:
+        return None
+    
+def get_shared_instance_module(user, module, student_module_cache):
+    """
+    Return shared_module is a StudentModule specific to all modules with the same
+        'shared_state_key' attribute, or None if the module does not elect to
+        share state
+    """
+    if user.is_authenticated():
+        # To get the shared_state_key, we need to descriptor
+        descriptor = modulestore().get_item(module.location)
+        
+        shared_state_key = getattr(module, 'shared_state_key', None)
+        if shared_state_key is not None:
+            shared_module = student_module_cache.lookup(module.category,
+                                                        shared_state_key)
+            if not shared_module:
+                shared_module = StudentModule(
+                    student=user,
+                    module_type=descriptor.category,
+                    module_state_key=shared_state_key,
+                    state=module.get_shared_state())
+                shared_module.save()
+                student_module_cache.append(shared_module)
+        else:
+            shared_module = None
+        
+        return shared_module
+    else:
+        return None
 
 
 @csrf_exempt
@@ -240,8 +269,10 @@ def xqueue_callback(request, userid, id, dispatch):
     # Retrieve target StudentModule
     user = User.objects.get(id=userid)
 
-    student_module_cache = StudentModuleCache(user, modulestore().get_item(id))
-    instance, instance_module, shared_module, module_type = get_module(request.user, request, id, student_module_cache)
+    student_module_cache = StudentModuleCache.cache_for_descriptor_descendents(user, modulestore().get_item(id))
+    instance = get_module(request.user, request, id, student_module_cache)
+    
+    instance_module = get_instance_module(request.user, instance, student_module_cache)
 
     if instance_module is None:
         log.debug("Couldn't find module '%s' for user '%s'",
@@ -285,16 +316,18 @@ def modx_dispatch(request, dispatch=None, id=None):
       - id -- the module id. Used to look up the XModule instance
     '''
     # ''' (fix emacs broken parsing)
-
     # Check for submitted files
     p = request.POST.copy()
     if request.FILES:
         for inputfile_id in request.FILES.keys():
             p[inputfile_id] = request.FILES[inputfile_id]
 
-    student_module_cache = StudentModuleCache(request.user, modulestore().get_item(id))
-    instance, instance_module, shared_module, module_type = get_module(request.user, request, id, student_module_cache)
+    student_module_cache = StudentModuleCache.cache_for_descriptor_descendents(request.user, modulestore().get_item(id))
+    instance = get_module(request.user, request, id, student_module_cache)
 
+    instance_module = get_instance_module(request.user, instance, student_module_cache)
+    shared_module = get_shared_instance_module(request.user, instance, student_module_cache)
+    
     # Don't track state for anonymous users (who don't have student modules)
     if instance_module is not None:
         oldgrade = instance_module.grade
diff --git a/lms/djangoapps/courseware/views.py b/lms/djangoapps/courseware/views.py
index f014e3fcb5..ac00626063 100644
--- a/lms/djangoapps/courseware/views.py
+++ b/lms/djangoapps/courseware/views.py
@@ -34,7 +34,6 @@ log = logging.getLogger("mitx.courseware")
 
 template_imports = {'urllib': urllib}
 
-
 def user_groups(user):
     if not user.is_authenticated():
         return []
@@ -45,6 +44,8 @@ def user_groups(user):
 
     # Kill caching on dev machines -- we switch groups a lot
     group_names = cache.get(key)
+    if settings.DEBUG:
+        group_names = None
 
     if group_names is None:
         group_names = [u.name for u in UserTestGroup.objects.filter(users=user)]
@@ -68,18 +69,17 @@ def gradebook(request, course_id):
     if 'course_admin' not in user_groups(request.user):
         raise Http404
     course = check_course(course_id)
-
+        
     student_objects = User.objects.all()[:100]
     student_info = []
-
-    for student in student_objects:
-        student_module_cache = StudentModuleCache(student, course)
-        course, _, _, _ = get_module(request.user, request, course.location, student_module_cache)
+    
+    #TODO: Only select students who are in the course
+    for student in student_objects:        
         student_info.append({
             'username': student.username,
             'id': student.id,
             'email': student.email,
-            'grade_info': grades.grade_sheet(student, course, student_module_cache),
+            'grade_summary': grades.grade(student, request, course),
             'realname': UserProfile.objects.get(user=student).name
         })
 
@@ -102,18 +102,23 @@ def profile(request, course_id, student_id=None):
 
     user_info = UserProfile.objects.get(user=student)
 
-    student_module_cache = StudentModuleCache(request.user, course)
-    course_module, _, _, _ = get_module(request.user, request, course.location, student_module_cache)
-
+    student_module_cache = StudentModuleCache.cache_for_descriptor_descendents(request.user, course)
+    course_module = get_module(request.user, request, course.location, student_module_cache)
+    
+    courseware_summary = grades.progress_summary(student, course_module, course.grader, student_module_cache)
+    grade_summary = grades.grade(request.user, request, course, student_module_cache)
+    
     context = {'name': user_info.name,
                'username': student.username,
                'location': user_info.location,
                'language': user_info.language,
                'email': student.email,
                'course': course,
-               'csrf': csrf(request)['csrf_token']
+               'csrf': csrf(request)['csrf_token'],
+               'courseware_summary' : courseware_summary,
+               'grade_summary' : grade_summary
                }
-    context.update(grades.grade_sheet(student, course_module, course.grader, student_module_cache))
+    context.update()
 
     return render_to_response('profile.html', context)
 
@@ -184,11 +189,12 @@ def index(request, course_id, chapter=None, section=None,
         if look_for_module:
             section_descriptor = get_section(course, chapter, section)
             if section_descriptor is not None:
-                student_module_cache = StudentModuleCache(request.user,
+                student_module_cache = StudentModuleCache.cache_for_descriptor_descendents(
+                                                          request.user,
                                                           section_descriptor)
-                module, _, _, _ = get_module(request.user, request,
-                                             section_descriptor.location,
-                                             student_module_cache)
+                module = get_module(request.user, request,
+                                    section_descriptor.location,
+                                    student_module_cache)
                 context['content'] = module.get_html()
             else:
                 log.warning("Couldn't find a section descriptor for course_id '{0}',"
diff --git a/lms/templates/gradebook.html b/lms/templates/gradebook.html
index bcc0456711..e5721969e9 100644
--- a/lms/templates/gradebook.html
+++ b/lms/templates/gradebook.html
@@ -8,6 +8,7 @@
 </%block>
 
 <%block name="headextra">
+  <%static:css group='course'/>
   
   <style type="text/css">
   .grade_a {color:green;}
@@ -19,7 +20,8 @@
   
 </%block>
 
-<%include file="navigation.html" args="active_page=''" />
+<%include file="course_navigation.html" args="active_page=''" />
+
 <section class="container">
 <div class="gradebook-wrapper">
   <section class="gradebook-content">
@@ -28,7 +30,7 @@
     %if len(students) > 0:
     <table>
       <%
-      templateSummary = students[0]['grade_info']['grade_summary']
+      templateSummary = students[0]['grade_summary']
       %>
       
       
@@ -42,15 +44,15 @@
       
       <%def name="percent_data(percentage)">
         <%
-          data_class = "grade_none"
-          if percentage > .87:
-            data_class = "grade_a"
-          elif percentage > .70:
-            data_class = "grade_b"
-          elif percentage > .6:
-            data_class = "grade_c"
-          elif percentage > 0:
-              data_class = "grade_f"
+          letter_grade = 'None'
+          if percentage > 0:
+            letter_grade = 'F'
+            for grade in ['A', 'B', 'C']:
+              if percentage >= course.grade_cutoffs[grade]:
+                letter_grade = grade
+                break
+          
+          data_class = "grade_" + letter_grade
         %>
         <td class="${data_class}">${ "{0:.0%}".format( percentage ) }</td>
       </%def>
@@ -58,10 +60,10 @@
       %for student in students:
       <tr>
         <td><a href="/profile/${student['id']}/">${student['username']}</a></td>
-        %for section in student['grade_info']['grade_summary']['section_breakdown']:
+        %for section in student['grade_summary']['section_breakdown']:
           ${percent_data( section['percent'] )}
         %endfor
-        <th>${percent_data( student['grade_info']['grade_summary']['percent'])}</th>
+        <th>${percent_data( student['grade_summary']['percent'])}</th>
       </tr>
       %endfor
     </table>
diff --git a/lms/templates/profile.html b/lms/templates/profile.html
index 8107bb1923..9fd0055d60 100644
--- a/lms/templates/profile.html
+++ b/lms/templates/profile.html
@@ -18,7 +18,7 @@
 <script type="text/javascript" src="${static.url('js/vendor/flot/jquery.flot.stack.js')}"></script>
 <script type="text/javascript" src="${static.url('js/vendor/flot/jquery.flot.symbol.js')}"></script>
 <script>
-${profile_graphs.body(grade_summary, "grade-detail-graph")}
+${profile_graphs.body(grade_summary, course.grade_cutoffs, "grade-detail-graph")}
 </script>
 
 <script>
diff --git a/lms/templates/profile_graphs.js b/lms/templates/profile_graphs.js
index 58dbeb8ed9..9826250331 100644
--- a/lms/templates/profile_graphs.js
+++ b/lms/templates/profile_graphs.js
@@ -1,6 +1,7 @@
-<%page args="grade_summary, graph_div_id, **kwargs"/>
+<%page args="grade_summary, grade_cutoffs, graph_div_id, **kwargs"/>
 <%!
   import json
+  import math
 %>
 
 $(function () {
@@ -89,8 +90,16 @@ $(function () {
   ticks += [ [overviewBarX, "Total"] ]
   tickIndex += 1 + sectionSpacer
   
-  totalScore = grade_summary['percent']
+  totalScore = math.floor(grade_summary['percent'] * 100) / 100 #We floor it to the nearest percent, 80.9 won't show up like a 90 (an A)
   detail_tooltips['Dropped Scores'] = dropped_score_tooltips
+  
+  
+  ## ----------------------------- Grade cutoffs ------------------------- ##
+  
+  grade_cutoff_ticks = [ [1, "100%"], [0, "0%"] ]
+  for grade in ['A', 'B', 'C']:
+      percent = grade_cutoffs[grade]
+      grade_cutoff_ticks.append( [ percent, "{0} {1:.0%}".format(grade, percent) ] )
   %>
   
   var series = ${ json.dumps( series ) };
@@ -98,6 +107,7 @@ $(function () {
   var bottomTicks = ${ json.dumps(bottomTicks) };
   var detail_tooltips = ${ json.dumps(detail_tooltips) };
   var droppedScores = ${ json.dumps(droppedScores) };
+  var grade_cutoff_ticks = ${ json.dumps(grade_cutoff_ticks) }
   
   //Alwasy be sure that one series has the xaxis set to 2, or the second xaxis labels won't show up
   series.push( {label: 'Dropped Scores', data: droppedScores, points: {symbol: "cross", show: true, radius: 3}, bars: {show: false}, color: "#333"} );
@@ -107,10 +117,10 @@ $(function () {
               lines: {show: false, steps: false },
               bars: {show: true, barWidth: 0.8, align: 'center', lineWidth: 0, fill: .8 },},
     xaxis: {tickLength: 0, min: 0.0, max: ${tickIndex - sectionSpacer}, ticks: ticks, labelAngle: 90},
-    yaxis: {ticks: [[1, "100%"], [0.87, "A 87%"], [0.7, "B 70%"], [0.6, "C 60%"], [0, "0%"]], min: 0.0, max: 1.0, labelWidth: 50},
+    yaxis: {ticks: grade_cutoff_ticks, min: 0.0, max: 1.0, labelWidth: 50},
     grid: { hoverable: true, clickable: true, borderWidth: 1,
-      markings: [ {yaxis: {from: 0.87, to: 1 }, color: "#ddd"}, {yaxis: {from: 0.7, to: 0.87 }, color: "#e9e9e9"}, 
-                  {yaxis: {from: 0.6, to: 0.7 }, color: "#f3f3f3"}, ] },
+      markings: [ {yaxis: {from: ${grade_cutoffs['A']}, to: 1 }, color: "#ddd"}, {yaxis: {from: ${grade_cutoffs['B']}, to: ${grade_cutoffs['A']} }, color: "#e9e9e9"}, 
+                  {yaxis: {from: ${grade_cutoffs['C']}, to: ${grade_cutoffs['B']} }, color: "#f3f3f3"}, ] },
     legend: {show: false},
   };
   
diff --git a/lms/urls.py b/lms/urls.py
index 9dc317039e..0d6b3b64b9 100644
--- a/lms/urls.py
+++ b/lms/urls.py
@@ -107,7 +107,6 @@ if settings.COURSEWARE_ENABLED:
 
         # TODO: These views need to be updated before they work
         # url(r'^calculate$', 'util.views.calculate'),
-        # url(r'^gradebook$', 'courseware.views.gradebook'),
         # TODO: We should probably remove the circuit package. I believe it was only used in the old way of saving wiki circuits for the wiki
         # url(r'^edit_circuit/(?P<circuit>[^/]*)$', 'circuit.views.edit_circuit'),
         # url(r'^save_circuit/(?P<circuit>[^/]*)$', 'circuit.views.save_circuit'),
@@ -119,7 +118,7 @@ if settings.COURSEWARE_ENABLED:
         #About the course
         url(r'^courses/(?P<course_id>[^/]+/[^/]+/[^/]+)/about$',
             'courseware.views.course_about', name="about_course"),
-
+        
         #Inside the course
         url(r'^courses/(?P<course_id>[^/]+/[^/]+/[^/]+)/info$',
             'courseware.views.course_info', name="info"),
@@ -137,6 +136,10 @@ if settings.COURSEWARE_ENABLED:
             'courseware.views.profile', name="profile"),
         url(r'^courses/(?P<course_id>[^/]+/[^/]+/[^/]+)/profile/(?P<student_id>[^/]*)/$',
             'courseware.views.profile'),
+        
+        # For the instructor
+        url(r'^courses/(?P<course_id>[^/]+/[^/]+/[^/]+)/gradebook$',
+            'courseware.views.gradebook'),        
     )
 
     # Multicourse wiki