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DrVirgo
Forum Junior Topics: 731 Posts: 3487 
What is the probability of making a type I error? what is the prob. of making a type II error?  
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DrVirgo
Forum Junior Topics: 731 Posts: 3487 
Which is worse?  
satyaking
Forum Junior Topics: 5 Posts: 54 
The probability of making type I erroris alpha,P<0.05. The probability of making type II error is beta.  
satyaking
Forum Junior Topics: 5 Posts: 54 
The probability of making type I erroris alpha,P<0.05. The probability of making type II error is beta.  
satyaking
Forum Junior Topics: 5 Posts: 54 
Type I error generally represents False negative,that is as P becomes less than 0.05 the false negative are going to be decreased.In the same way in Type II error the power of the test is denoted by 1 Beta.the power represents the true negatives where as beta represents the false positives.hence a balance should be struck so that there is a balance between them.but most clinical research studies P less than 0.01.hence as cut off point is very low the alpha error is decreased but there is a chance of increased beta error,that is false pos.. are increased.and vice versa occurs.hence balace should be struck between the two. hope Iam clear about it  
jonathon
Forum Senior Topics: 25 Posts: 62 
I think alpha error is worse. It's like saying a drug does produce a clinically significant when in fact it does not..(Like a Lie). A type 2 error is like saying a drug does not work when it fact it does have therapeutic significance. ??? I think this is it..correct me if i'm wrong.  
DrVirgo
Forum Junior Topics: 731 Posts: 3487 
You all are right. The probability of making a type I Error is alpha or The probability of making a type II Error is Beta. Beta=1Power. Now whats the answer to this Q? and WHY??? 8. A group of researchers mistakenly conclude from a poorly designed experiment that acetaminophen cures the common cold. They have committed which of the following?<?xml:namespace prefix = o ns = "urn:schemasmicrosoftcom:office:office" /> A. 1β error B. Alpha error C. Beta error D. Type I error E. Type II error  
satyaking
Forum Junior Topics: 5 Posts: 54 
Type II error,because they have would taken alpha very less hence more chance of type II error  
sturge_weber
Forum Guru Topics: 77 Posts: 1034 
i think alpha error  
sarika
Forum Guru Topics: 193 Posts: 1188 
ans:type 1 error alpha is the probability of making type one error .  
DrVirgo
Forum Junior Topics: 731 Posts: 3487 
The correct answer is D. Type I errors occur when researchers reject the null hypothesis when they should not have. In other words, they conclude a significant result when in actuality it does not exist. This is a particularly dangerous error to make, as it could lead to the administration of an ineffective drug to patients in need of lifepreserving treatment. <?xml:namespace prefix = o ns = "urn:schemasmicrosoftcom:office:office" /> Thanks everyone. To conclude: Type I error is worse alpha is the probability of making a type I Error. Type II error = 1Power (Type II error (beta error) does NOT equal alpha!)  
mjl1717
Forum Junior Topics: 964 Posts: 5442 
Very good Dr. Virgo, because the definitions of both may appear as "double talk" to many". But in inactuality this is a significant part of biostat and epidemiolgy.  
leen
Forum Elite Topics: 79 Posts: 294 
thanks  
zubr
Forum Junior Topics: 14 Posts: 61 
Is Type I error the same as alpha error? Where is this question coming from? I assume that is not from actual USMLE exam, or from NBME. Alpha = I = False Positive (in reality it is false, but was mistakebly accepted by study as truth, a bad drug but shown as a good one = LIE) ONLY if we reject H(0) but must not  alpha(I) error ONLY Rejecting H(0) we could make alpha(I) error with chance 5% (5 from 100, 1 from 20) if p=0.05 Beta= II = False Negative (in reality it is truth, but was rejected, a good drug but shown as a bad one = MISTAKE) ONLY if we accept H(0) but must not  beta(II) error ONLY Accepting H(0) we could make beta(II) error with chance 1Power (p=0.05 does not matter) LIE(I) is worst then MISTAKE(II) REALITY TRUTH(+)FALSE() STUDY SHOW TRUTH (+)TPFP(I)alpha STUDY SHOW FALSE ()FN(II)betaTN TP=POWER= 1  beta  
mohammem
Forum Newbie Topics: 2 Posts: 198 
TYPE ONE ERROR,,,YOU REJECT NULL HYPOTHESIS(COZ YOU MARKETING UNEFFECTIVE DRUG),,,,GOOD LUCK IF IN EXAME NO THOUGHT BLOCK!!!!!  
drgbolls
Forum Junior Topics: 20 Posts: 211 
alfa or type 1 error is actually false positive!!  
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