**Abstract of Chapter 9**

$(\sharp):$ | $ \underset{(=\mbox{ quantum language})}{\mbox{measurement theory}} \left\{\begin{array}{ll} \underset{\mbox{($\sharp_1$)}}{ \mbox{pure type}} \left\{\begin{array}{ll} \!\! \mbox{classical system} : \mbox{ Fisher statistics} \\ \!\! \mbox{ quantum system} : \mbox{ usual quantum mechanics } \\ \end{array}\right. \\ \\ \underset{\mbox{($\sharp_2$)}} {\mbox{mixed type}} \left\{\begin{array}{ll} \!\! \mbox{ classical system} : \mbox{including Bayesian statistics, }\\ \qquad \qquad \qquad \qquad \mbox{Kalman filter} \\ \!\! \mbox{ quantum system} : \mbox{ quantum decoherence } \\ \end{array}\right. \end{array}\right. $ |

In this chapter, we study

**mixed measurement theory, which includes Bayesian statistics.**

**Again recall that, as mentioned in $\S$1.1, the main purpose of this book is to
assert the following figure 1.1:**

**Fig.1.1: the location of "quantum language" in the world-views**