fixes for clarity

app/lib/irt/item_information_function.py

@@ -4,6 +4,9 @@ class ItemInformationFunction():
   def __init__(self, irt_model):
     self.model_data = irt_model
 
+  # determines the amount of information for a given question at a given theta (ability level)
+  # further detailed on page 161, equation 4 here:
+  #  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5978482/pdf/10.1177_0146621615613308.pdf
   def calculate(self, **kwargs):
     if self.model_data.model == '3PL':
       p = ThreeParameterLogistic(self.model_data, kwargs).result()

app/lib/irt/models/three_parameter_logistic.py

@@ -6,6 +6,10 @@ class ThreeParameterLogistic:
     self.e = 2.71828
     self.theta = kwargs['theta']
 
+  # contains the primary 3pl function, determining the probably of an inidividual
+  # that an individual at a certain theta would get a particular question correct
+  #  detailed further on page 161, equation 1 here:
+  # https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5978482/pdf/10.1177_0146621615613308.pdf
   def result(self):
     a = self.model_params.a_param
     c = self.model_params.c_param

app/lib/irt/test_information_function.py

@@ -5,6 +5,10 @@ class TestInformationFunction():
     self.irt_model = irt_model
     self.iif = ItemInformationFunction(irt_model)
 
+  # determins the amount of information
+  # at a certain theta (ability level) of the sum of a question set correct
+  # detailed further on page 166, equation 4 here:
+  # https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5978482/pdf/10.1177_0146621615613308.pdf
   def calculate(self, items, **kwargs):
     sum = 0
 

app/lib/irt/test_response_function.py

@@ -6,6 +6,10 @@ class TestResponseFunction():
     self.irt_model = irt_model
     self.irf = ItemResponseFunction(irt_model)
 
+  # determins the probably of an inidividual
+  # at a certain theta (ability level) would get a sum of questions correct
+  # detailed further on page 166, equation 3 here:
+  # https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5978482/pdf/10.1177_0146621615613308.pdf
   def calculate(self, items, **kwargs):
     sum = 0