Subjective probability

Subjective probability (subjective probability) of the definition

1. Reasonable belief measure
2. Possible measure someone happens to a specific event; that is, he believed that the degree of likelihood size (think) events will occur. The extent of this I believe is a belief, is subjective, but is based on experience, knowledge of all aspects, to understand the objective situation analysis, reasoning, judgment and comprehensive set (Assignment) of the guesswork different.
3. Subjective probability is a state of mind or tendentious description of the event.
4. Subjective probability, is built on the past experience and judgment probability based on a study of the future developments of forecasting and historical statistics determined. Reflects only a subjective possibility [1].
5. A quantitative indicator of how likely a situation (event) occur.

Guidelines subjective probabilities

1. Make a judgment based on experience or knowledge
2. Make judgments based on the stakes events

Subjective probability Case

There are four hunters, are: Zhang, Li, Xiao Ming, flowers. They meet early in the morning into the mountains to hunt. To solve this problem the number of hunting with bow and arrow into the mountains, they

\ (A = \) {} today hunting destination without prey

The possibility of the size of this happening judgment. The four hunters assumed hunting experience or confidence in the hunting area, they gave the following determination

• Zhang believes \ (A \) size occurs is 0; ------------------- mean, \ (A \) can not happen
• Li believes \ (A \) size of 0.3 occurred; ----------------- mean, \ (A \) a low probability of occurrence
• Xiao Ming think \ (A \) size of 0.8 occurred; ----------------- mean, \ (A \) the probability of occurrence of large
• Florets think \ (A \) size occur is 1; ------------------- mean, \ (A \) must have occurred 100%

The above probabilities \ (0, 0.3, 0.8, 1 \) reflects the four hunters of the event \ (A \) a subjective estimate, which is subjective probability . Come to this estimate, the consequences are different:

• Zhang believes \ (A \) size occurs is 0; ------------------- mean, \ (A \) can not happen ------ -------------- consequences: Zhang will take a lot of bows and arrows into the mountains
• Li believes \ (A \) size of 0.3 occurred; ----------------- mean, \ (A \) the probability of occurrence of small ------ -------- consequences: Li will bring more into the mountains bow and arrow
• Xiao Ming think \ (A \) size of 0.8 occurred; ----------------- mean, \ (A \) the probability of occurrence of large ------- ---- consequences: Xiao Ming will take less of a bow and arrow
• Florets think \ (A \) size occur is 1; ------------------- mean, \ (A \) must have occurred ------ 100% --------- consequences: the flowers will not take a bow and arrow into the mountains, it will take a lot of basket, into the mountains to cut firewood

Many things are inevitably contain ingredients subjective judgment, which is subjective probability.

related question

1. Why the introduction of subjective probability?
   (1) Some natural state can not be repeated trials; such as: whether it rains tomorrow; how the new product sales; how national economic growth rate next year; whether admitted to doctoral students;
   (2) the cost of the test is too expensive, the cost is too large; Cases : Chau missile hit rate; war estimate of the enemy's next move

Reference material

[1] Baidu Encyclopedia