class KnowledgeManager(object):
"""
This is the class that manages students' performance and update his/her
estimated knowledge level
"""
#Init
def __init__(self, KL = None, KM = None):
#student KL (knowledge level)
if (KL == None):
self._KL = DecayKnowledgeLevel()
else:
self._KL = KL
#student KM (knowledge model)
if (KM == None):
self._KM = PointKnowledgeModel()
else:
self._KM = KM
#Knowledge graph
self._KG = KnowledgeGraph()
#Knowledge level of DB
self._knowledgeLevel = {}
#Knowledge graph of DB
#This variable is for every student
self._knowledgeGraph = {}
#Temporary DB
self.tmpDB = DummyDB()
#An estimator which is used for calculate estimated KL based on the performance
self._estimator = KnowledgeEstimator()
#Bind a KM to the KL as its observer
self._KL.addObserver(self._KM)
#Bind a KM to the KG as its observer
self._KG.addObserver(self._KM)
@classmethod
def initWithKL(cls, KL = None):
if (isinstance(KL, BaseKnowledgeLevel)):
return cls(KL, None)
else:
raise TypeError("Input is not an acceptable type of KL(knowledge level) object!")
@classmethod
def initWithKM(cls, KM = None):
if (isinstance(KM, BaseKnowledgeModel)):
return cls(None, KM)
else:
raise TypeError("Input is not an acceptable type of KM(knowledge Model) object!")
@classmethod
def initWithKLAndKM(cls, KL = None, KM = None):
if (isinstance(KL, BaseKnowledgeLevel)):
if (isinstance(KM, BaseKnowledgeModel)):
return cls(KL, KM)
else:
raise TypeError("Input is not an acceptable type of KM(knowledge Model) object!")
else:
raise TypeError("Input is not an acceptable type of KL(knowledge level) object!")
#Initialize the parameters about KL for a certain student
def initKnowledgeLevel(self, studentID = None):
if (studentID == None):
raise ValueError("Input student Id is not available!")
#Create a knowledge level table for the student
studentKL = self._knowledgeLevel.get(studentID)
self._KL.setKnowledge(studentKL)
#Initialize the estimation in KM
self._KM.setKnowledge(studentKL)
#Initialize the parameters about KG
def initKnowledgeGraph(self):
self._KG.setDependency(self._knowledgeGraph)
self._KG.updateConcept() #Because KG involves constant values only, its content needs to be update once only
#Pass the ALEKS score
def setALEKS(self, aleks = None):
if (aleks == None):
raise ValueError("Input ALEKS score is not available!")
self._KL.setALEKS(aleks)
#Save the student's performance and update his/her estimated knowledge level
def savePerformance(self, studentID = None, conceptID = None, hints = None, prompts = None, summary = None, lcc = None):
if (studentID == None):
raise ValueError("Input student Id is not available!")
if (conceptID == None):
raise ValueError("Input concept Id is not available!")
if (hints == None or hints < 0):
raise ValueError("Hints value is invalid! (0, 1, 2, ..., n)")
if (prompts == None or prompts < 0):
raise ValueError("Prompts value is invalid! (0, 1, 2, ..., n)")
if (summary != True and summary != False):
raise ValueError("Prompts value is invalid! (True or False)")
if (lcc == None or lcc < 0):
raise ValueError("LCC score value is invalid! (0~1)")
#Caculate the observed estimation about knowledge level based on the student's performance
obsEst = self._estimator(hints, prompts, summary, lcc)
#Update the estimation
self._KL.updateKnowledge(conceptID, obsEst)
#Save updated estimation back to the knowledge level table
#(The table need to be saved back to the DB later)
self._knowledgeLevel[studentID] = self._KL.getKnowledge()
def getKnowledgeLevel(self, conceptID = None):
if (conceptID == None):
raise ValueError("Input concept id is not available!")
return self._KM.getKnowledgeLevel(conceptID)
def loadKnowledgeDB(self):
#TODO: Replace this temorary DB by real DB
self._knowledgeLevel = self.tmpDB._knowledge
def saveKnowledgeDB(self):
#TODO: Replace this temorary DB by real DB
self.tmpDB._knowledge = self._knowledgeLevel
def loadGraphDB(self):
#TODO: Replace this temorary DB by real DB
self._knowledgeGraph = self.tmpDB._dependency
def saveGraphDB(self):
#TODO: Replace this temorary DB by real DB
self.tmpDB._dependency = self._knowledgeGraph