Week 2 Flashcards
What is the simple confidence interval?
A range of values that we are confident contains the population parameter
What is point estimate?
A single value that represents the best estimate of the population value
In a confidence interval, the width concerns the ___ of the estimate
In a confidence interval, the width concerns the precision of the estimate
The point estimate is always in the ___ of the confidence interval
The point estimate is always in the middle of the confidence interval
What is the formal definition of a confidence interval?
If we repeated sampling an infinite number of times, 95% of the intervals would overlap the true mean
Not every value in a CI, is equally as ___
Not every value in a CI, is equally as probable
A more narrow confidence interval means that it is ____ precise
A more narrow confidence interval means that it is more precise
What are the factors that can narrow/increase a confidence interval?
- Larger sample size
- Less variance
- Lower selected level of
confidence (90% vs. 95%)
The null hypothesis is ___. And it states that _____
The null hypothesis is a sampling error. And it states that the population means(not sample means) are equal so the difference seen is not real
The alternative hypothesis states that the difference seen, represents __.
The alternative hypothesis states that the difference seen, represents a real difference.
What is a type 1 error in hypothesis testing? What is its symbol? This is considered a liar
When the null hypothesis is true, and we choose to reject it.
Symbol: “Alpha”
What is a type 2 error in hypothesis testing? What is its symbol? This is considered to be blind
When the null hypothesis is false, and we do not reject it. (accept it)
Symbol: Beta
___ is the maximum probability of type 1 error that a researcher is willing to accept
Alpha is the maximum probability of type 1 error that a researcher is willing to accept
When does the researcher set the alpha?
Set before running statistics
What is alpha usually set to?
0.05. (5%)
What is the simple definition of a p-value?
The probability of type 1 error if the null hypothesis is true
True or false.
You can have a probability of type 1 error what the null hypothesis is false
False
You can NOT have a probability of type 1 error what the null hypothesis is false
When is the p-value calculated?
After research
What is the formal definition of a p-value?
Probability of observing a value more extreme than actual value observed, if the null hypothesis is true
If the p-value is less than or equal to alpha, we ___ the null hypothesis
If the p-value is less than or equal to alpha, we REJECT the null hypothesis
If the p-value is greater than or equal to alpha, we ___ the null hypothesis
If the p-value is greater than or equal to alpha, we ACCEPT the null hypothesis
If we “fail to reject” (accept) Ho, we attribute any
observed difference to ____ only
If we “fail to reject” (accept) Ho, we attribute any
observed difference to sampling error only