Independent samples t-tests
Hypothesis tests analyzed with related samples ttests
Let's start with a brief review. In the last several labs we looked at ways to test samples.
We used z-scores to test whether a sample was probably from a population
This first lab will be short. Don't get used to having labs being this short all the time.
I am going to try to save as much paper as I can this semester by having you submit your work
electronically. This means that in the future I w
So far, you've learned the z-test and the 1-sample t-test. These are legitimate statistical tests
but, truth be told, they aren't all that practical. The reason for this is that it is rare that you would
know the population m
Use this file which represents the results of study on the effects of psychotherapy on aggression
and empathy. 38 participants filled out a questionnaire measuring their aggressiveness and
empathy before and after therapy.
The one-sample t-test allows us to extend our hypothesis testing procedure to cases where we
dont know the population standard deviation . Without the population , we cant directly
calculate the standard error like we would do for
Confidence Intervals with t
Confidence intervals with t are just like confidence intervals with z. Review Lab 15 if you need a
full explanation of what a confidence interval is.
The previous formula for confidence intervals is:
In a 1-sample situat
Regression & Correlation as hypothesis tests
It turns out that in addition to the 4 statistical tests we've learned so far, you already know 2
more. Remember regression and correlation? Those can be considered hypothesis tests, too.
Occupational Therapy and Psychological Disorders
What is Occupational Therapy? According to the AOTA (American Occupational Therapy
Association), Occupational Therapy is characterized as helping people across lifespan