Loading....
Coupon Accepted Successfully!

PSM

Open Flashcards

Biostatistics

Question
40 out of 76
 

All are true except: (DNB Dec 2009)



A α is the maximum tolerable probability of type – I error

B β is the probability of type – II error

C When null hypothesis is true but is rejected, it is type – II error

D P- value can be more or less than α

Ans. C When null hypothesis is true but is rejected, it is type – II error Ref: High Yield Biostatistics, Pg: 35-36

Two types of errors can be made in the test of hypothesis:

Type I Error:- That is the rejection of null hypothesis in spite being true

Also called as False positive error i.e. in reality there is no difference but the study has concluded a difference.

The probability of committing type I error is P value. Hence please remember it as a rule: Any question based on p-value, you only have to look at that option that describes a type I error or a false positive error. Any option beginning with type II error or β or false negative error or the power of the study can never be the answer to this question.

Type II Error, Beta Error or False negative error: Accepting null hypothesis in spite being false. This also means that in reality there is a difference but the study has failed to detect that difference.

Power (1-Beta)is defined as the probability of rejecting the null hypothesis when it is false. Normally accepted value for power is 80%.

Levels of type I error are usually kept at or under 5%, the measure of type I error is also called the ‘p’ value. Thus a ‘p’ value < .05 means the probability of getting a difference as extreme as; or more, given the fact that in reality no difference exists is less than 5%, in other words, the difference because of chance; is less than 5%.

Biostatistics Flashcard List

76 flashcards
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
27)
28)
29)
30)
31)
32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
42)
43)
44)
45)
46)
47)
48)
49)
50)
51)
52)
53)
54)
55)
56)
57)
58)
59)
60)
61)
62)
63)
64)
65)
66)
67)
68)
69)
70)
71)
72)
73)
74)
75)
76)