Lecture 3- Sampling Flashcards
Define sampling error
A sample that doesnt represent the population
What does the p value represent
The probability that the null hypothesis is true.
The probability that an effect would be seen in a population where the null hypothesis is true.
What is a type 1 and type 2 error
A type 1 error is when we think there is an effect but there actually isnt
A type 2 error is when we think that there isnt an effect but there actually is.
What happens when you reject the null hypothesis
This means that the probability that there is no effect in the population is less than .05.
What happens when you accept the null hypothesis
This means that the probability that there is no effect in the population is greater than .05.
How does the p value relate to standard error
IF the standard error is small, we dont have a lot of deviation between our sample and the population.
Therefore its unlikely we have made a sampling error.
Therefore, chances we have an effect in our sample but not in the population (type 1) is low.
Limitations of the p value
0.05 is an arbitrary number, encourages over reliance on finding results that are under the cut off.
How much % does a significant outcome have of making error
5%