An example of a necessary tool when coding subjective beliefs
into probabilities: correspondence between ordinary language expressions
and quantitative probabilities (from F. Mosteller and C. Youtz (1990).
Quantifying Probabilistic Expressions, Statistical Science, 5, 1, 2-34.)
|
Expression |
lower point |
upper point |
|
Expression |
lower point |
upper point |
|
|
|
|
|
|
|
|
|
Always |
99.6 |
99.8 |
|
Less often than not |
34.8 |
42.7 |
|
Almost always |
89.7 |
95.2 |
|
Not often |
10.3 |
24.8 |
|
|
|
|
|
|
|
|
|
Certain |
98.7 |
99.8 |
|
Not very often |
5.3 |
19.8 |
|
Almost certain |
87.5 |
95.0 |
|
Possible |
7.5 |
50.2 |
|
|
|
|
|
Impossible |
0.2 |
0.5 |
|
Very frequent |
75.3 |
89.7 |
|
High chance |
77.5 |
89.1 |
|
Frequent |
60.0 |
75.3 |
|
Better than even chance |
53.3 |
60.2 |
|
Not frequent |
32.7 |
57.3 |
|
Even chance |
49.7 |
50.2 |
|
Infrequent |
10.1 |
22.6 |
|
Less than an even chance |
45.0 |
39.6 |
|
Very infrequent |
3.6 |
10.0 |
|
Poor chance |
8.4 |
19.7 |
|
|
|
|
|
Low chance |
5.0 |
12.8 |
|
Very high probability |
89.8 |
95.2 |
|
Liable to happen |
59.8 |
77.7 |
|
High probability |
77.1 |
87.2 |
|
Might happen |
19.9 |
50.1 |
|
Moderate probability |
40.1 |
58.7 |
|
|
|
|
|
Low probability |
7.8 |
22.3 |
|
Usually |
65.6 |
82.2 |
|
Very low probability |
1.9 |
7.6 |
|
Unusually |
9.9 |
26.1 |
|
|
|
|
|
Sometimes |
17.5 |
35.0 |
|
Very likely |
80.1 |
90.2 |
|
Once in a while |
9.9 |
22.4 |
|
Likely |
62.6 |
77.6 |
|
Not unreasonable |
23.5 |
52.6 |
|
Unlikely |
9.8 |
22.7 |
|
Occasionally |
12.5 |
27.7 |
|
Very unlikely |
2.7 |
9.8 |
|
Now and then |
9.8 |
25.0 |
|
|
|
|
|
|
|
|
|
Very probable |
81.5 |
90.4 |
|
Seldom |
7.4 |
17.5 |
|
Probable |
64.7 |
77.7 |
|
Very seldom |
3.2 |
7.7 |
|
Improbable |
7.6 |
22.3 |
|
|
|
|
|
Very improbable |
1.5 |
7.5 |
|
Rarely |
3.6 |
10.0 |
|
|
|
|
|
Very rarely |
1.2 |
5.0 |
|
Very often |
77.5 |
89.9 |
|
Almost never |
1.2 |
4.6 |
|
Often |
65.0 |
75.4 |
|
Never |
0.1 |
0.4 |
|
More often than not |
57.1 |
60.4 |
|
Never |
0.1 |
0.4 |
|
As often as not |
49.8 |
50.3 |
|
|
|
|
|
|
|
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