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I don't know if ever I'll master biostatistics and questions of the like, please anyone who has a grip explain to me in the most lay mans terms what the null hypothesis is? what it means to accept of reject it, what that will do to the outcome of your study. what the p value denotes, its correlcation to the the acceptance or rejection of the null hypothesis, and all that it entails, from chi square to the other crap that I have never learned. I can't seem to excite just one cell in my body to allow the filtration of knowledge when it comes to epidimiology or biostats. pls pls help
thank u in advance
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anybody at all? at least the null hypothesis portion what does it mean to accept or reject it. I know it probably is a silly question for many, but I really don't know how interpert it, considering that sometimes the answer to the q lies entirly on accepting or rejecting the null hypothesis
thanks
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hi somber sorry for late reply i thought some body else can explain better than me but apparently every body was thinking the same ,and never say my silly q because every body has weak points and you are not exeption so feel comfortable to ask your problems like all of us,i try my best ... null hypothesis is the opposite thesis of what ever we think the result of our study would be for example if we want to see a new drug is functioning better than an old drug for same disease ---->null hypothesis would be that the effect of two drug(new,old)are the same ---->then look at given p value if it is less or the same as 0.05--->we reject null hypothesis ok? there is achance of error that we reject the null hypothesis but actually it is true that is type 1(alpha)of error which we can say amount of it base on p value if p value is 0.02 for example--->type1 error chance is 2%ok? then some times p value is more than 0.05--->we can not reject null hypothesis(attention: it doesnt mean that we accept it) --->this time there is a chance of type2 error (beta) which means that we did not reject null hypothesis even though it was wrong unlike type1 error ,type2 has nothing to do with p value but is a relationship with power power=1-beta i hope that helps if you have any q plz ask me specifically your problem ,gl
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wow so complicated, I don't know why biostats and things of the like are such a challenge for me, thanks so much for your time I am much obliged. if you have a question sample and we can go over it togther just to make sure I fully grasp, to be honest I think I do but not sure =(
also do you know when we use the chi square and other things like that?
Ijust barely got a grasp on the z score, someone was kind enough to tell me the number is a contant, I didn't know where the values were coming from in that formula, God have mercy on us
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Hi Somber,
Mahshid has given a very well rounded reply to your question. I found it very useful.
I wanted to see if I could articulate my understanding of the null hypothesis and thought it might help add perspective.
Now if one conducts a study, one can use an approach called Hypothesis testing to determine whether the results CHALLENGE or CONFIRM the existing scientific belief(Percieved truth/Prevailing Dogma)
The process involves articulating two statements(Hypotheses)...namely
1. The Null Hypothesis : Which simply states existing scientific belief
and
2. The Alternate Hypothesis : Which challenges the existing viewpoint.
For example,
If existing belief is that the normal blood glucose level is say 80-120 mg / dl, Then this would be the null hypothesis and the challenging statement i.e. That the Normal Blood Glucose is not 80-120 mg / dl would be the Alternate Hypothesis.
If one entertains both a possibilty of the blood glucose level being either lower than 80-120mg/dl or higher, one calls this a two-sided(tailed) alternate hypothesis but if one entertains only one alternate possibility (i.e. it being either more than or less than the range conventionally held to be true, it is referred to as a one-sided(tailed) alternate hypothesis.
I hope you find this useful.
Thanks for starting the discussion.
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it is very helpful thank you, I guess I often think of the word "null" as zero or nonexisting so it is engraved in my mind and I can't at first glance force myself to believe it to be anything but just "wrong hypothesis" to be accepted or rejected.
thanks to you both again
