:<math> A \leftarrow B \rightarrow C \rightarrow A</math>
:<math> A \leftarrow B \rightarrow C \rightarrow A</math>
−
在这样的模型中,<math> B </math>是<math> A </math>和<math> C </math>的共同原因( <math>C</math> 也是<math> A </math>的原因),这使<math>B</math>成为'''<font color="#ff8000"> 混杂因子 Confounder </font>'''。{{clarify|reason=Why is this case interesting? Why is B called a cofounder?|date=January 2019}}.<ref name=":1" />{{rp|[{{google books|plainurl=y|id=9H0dDQAAQBAJ|page=114}} 114]}}
+
在这样的模型中,<math> B </math>是<math> A </math>和<math> C </math>的共同原因( <math>C</math> 也是<math> A </math>的原因),这使<math>B</math>成为'''<font color="#ff8000"> 混杂因子 Confounder </font>'''。{{clarify|reason=Why is this case interesting? Why is B called a cofounder?|date=January 2019}}.<ref name=":1" />