Philosphy week 6

Philosphy week 6 - If being right about the difference is...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
What is the probability that the difference in the sample could have resulted by chance had there been no difference in the population. The hypothesis that there there is no difference between the means of the two groups is known as the null hypothesis Strategy: try to reject the null hypothesis Conclude that there is a difference in the real population when the sample you get would be very unlikely were the null hypothesis true. Just as with correlations, we use the notion of statistical significance to evaluate results. A difference in a sample is said to be statistically significiant when it has a very low probability of occurring if the means in the population are equal. Less then 5% is significant.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: If being right about the difference is more important, use higher significance levels, If missing a difference that really exists is more important to avoid, use might accept a lower significant levels. If the difference in your sample is not statistically significant, you conclude that you cannot tell whether there is actually a difference in the real population There may be one, but the power of your test was too weak to find it It is important to keep in mind that we impose a high standard on significance Typer 1 error ( overconfidence): thinking there is a difference between means where is non Type 2 error ( humility): thinking there is none, even though there is. 1....
View Full Document

This note was uploaded on 09/13/2011 for the course PHIL 12 taught by Professor Matthewbrown during the Spring '08 term at UCSD.

Ask a homework question - tutors are online