diff --git a/app/lib/irt/item_information_function.py b/app/lib/irt/item_information_function.py
index ddb3cbb..29d6b90 100644
--- a/app/lib/irt/item_information_function.py
+++ b/app/lib/irt/item_information_function.py
@@ -11,7 +11,7 @@ class ItemInformationFunction():
     if self.model_data.model == '3PL':
       p = ThreeParameterLogistic(self.model_data, kwargs).result()
       q = 1 - p
-      return self.model_data.a_param**2 * ((q / p) * ((p - (self.model_data.c_param**2)) / (1 - (self.model_data.c_param**2))))
+      return (self.model_data.a_param * q * (p - self.model_data.c_param)**2) / (p * ((1 - self.model_data.c_param)**2))
     else:
       # potentially error out
       return None