attractive ppt on hypothesis by ammara aftab
TRANSCRIPT
BY AMMARA AFTAB
THE GAME OF
CERTAINITY
Certainty is the perfect knowledge that has a total security from errors, or the mental state is being without doubt.
“In this world nothing is to be certain except death and taxes”
------BENJAMIN FRANKLIN
UNCERTAINITY
The lack of certainity.A state of having limited knowledge where it is impossible to exactly describe the existing state or future outcome.“You can not be certain about certainty” ----DAVID THOMAS
BY AMMARA AFTAB
Jaints companies wants an ANGLE
BY AMMARA AFTAB
Instead of ANGLES they have STATISTICIAN
RONALD A FISHERBY AMMARA AFTAB
HYPOTHESIS…..???
BY AMMARA AFTAB
What’s this all about?• Hypothesis
• An educated guess
• An experienced guess
The goal in Hypothesis Testing is to analyze a sample in an attempt to distinguish between population characteristics that are likely to occur and population characteristics that are unlikely to occur.
BY AMMARA AFTAB
DEFINITION A proposition to be tested, predicts a
relationship b/w more than 2 variables.
(Webster’s New International Dictionary Of English)
A tentative statement about something, the validity of which is usually unknown.
(Black, James A Dean J Champion)
BY AMMARA AFTAB
FUNCTIONS
Bringing the clarity to the research problem.
Provide a study with focus. Signifies what specific aspect of a research
problem is to investigate. What data to b collected. Formulate the theory. Enable to conclude what is true or false.
BY AMMARA AFTAB
• Null Hypothesis vs. Alternative Hypothesis
• Type I vs. Type II Error
• vs.
The Basics
BY AMMARA AFTAB
Null Hypothesis vs. Alternative Hypothesis
Null Hypothesis
• Statement about the value of a population parameter
• Represented by H0• Always stated as an
Equality
Alternative Hypothesis
• Statement about the value of a population parameter that must be true if the null hypothesis is false
• Represented by H1
• Stated in on of three forms• >• <•
BY AMMARA AFTAB
Type I vs. Type II Error
Referring to Ho, the Null Hypothesis
True False
Reject Type I Error
O.K
Fail to Reject
O.K. Type I I Error
BY AMMARA AFTAB
BY AMMARA AFTAB
NowThe Main Thing Is
………….???????BY AMMARA AFTAB
INTERPRETATION
BY AMMARA AFTAB
Interpreting the p-value…
The smaller the p-value, the more statistical evidence exists to support the alternative hypothesis.
• If the p-value is less than 1%, there is overwhelming evidence that supports the alternative hypothesis.
• If the p-value is between 1% and 5%, there is a
BY AMMARA AFTAB
Interpreting the p-value…
• strong evidence that supports the alternative hypothesis.
• If the p-value is between 5% and 10% there is a weak evidence that supports the alternative hypothesis.
• If the p-value exceeds 10%, there is no evidence that supports the alternative hypothesis.
BY AMMARA AFTAB
Summary of One- and Two-Tail Tests…
I am the best. (In this situation)One-Tail Test
(left tail)Two-Tail Test One-Tail Test
(right tail)
BY AMMARA AFTAB
Type I and Type II Errors
True State of Nature
We decide to
reject the
null hypothesis
We fail to
reject the
null hypothesis
The null
hypothesis is
true
The null
hypothesis is
false
Type I error
(rejecting a true
null hypothesis)
Type II error
(rejecting a false
null hypothesis)
Correct
decision
Correct
decision
Dec
isio
n
BY AMMARA AFTAB
Forming Conclusions• Every hypothesis test ends with the experimenters (you
and I) either• Rejecting the Null Hypothesis, or• Failing to Reject the Null Hypothesis
• It may seem strange that, you never accept the Null Hypothesis. The best you can say about the Ho is that you don’t have enough evidence, based on a sample, to reject it!
• we do not say that we accept the null hypothesis
BY AMMARA AFTAB
Seven Steps to Hypothesis Testing Happiness
(Traditional or Classical Method)
BY AMMARA AFTAB
1) Describe in words the population characteristic about which hypotheses are to be tested
2) State the null hypothesis, Ho
3) State the alternative hypothesis, H1 or Ha
4) Display the test statistic to be used
The Seven Steps…
BY AMMARA AFTAB
5) Identify the rejection region
• Is it an upper, lower, or two-tailed test?
• Determine the critical value associated with , the level of significance of the test
6) Compute all the quantities in the test statistic, and compute the test statistic itself
The Seven Steps…
BY AMMARA AFTAB
The Seven Steps…
7) State the conclusion. That is, decide whether to reject the null hypothesis, Ho, or fail to reject the null hypothesis. The conclusion depends on the level of significance of the test. Also, remember to state your result in the context of the specific problem.
BY AMMARA AFTAB
THANKs tO
NOW ITS UNLOCK
SIR TAUQEER
Special
BY AMMARA AFTAB