Nonparametic statistics
10 important questions on Nonparametic statistics
How do we call the category of methods for comparing treatments without assuming a normal distribution for the response variable in the population?
How do you get numbers to perform a wilcoxon nonparametric test for comparing groups?
- take two independent groups
- create a table of all possible ranking combinations between participants
- take the mean ranking for each group on each combination
- for each combination, take the mean difference between groups
- create a sampling distribution with x-axis mean differences per combination, y-axis is probability of occurring
- then make the actual ranking of the participants and take the mean ranking dofference between groups.
How do you get to a conclusion using the wilcoxon nonparamtric test for comparing groups?
- make assumptions
- H0: identical population distributions, so equal expected values for sample mean differences
- H1: different values for sample mean differences, or higher sample mean differences
- test statistic: difference in sample mean ranking.
- p-value: sum of prob. of difference in sample means and all differnces in sample means above that.
- conclusion.
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
For my 1st exam I got a C. Then, I started looking for ways to learn better and I came across Study Smart. Since then I have scored a A+, A, A- and another A. I highly recommend it to everyone who wants to hear it. I am so happy with it!!
I was struggling to finish all my first-year subjects for 3 years. Then I discovered Study Smart, which helped me to finish all of them within 3 months.
Because of StudySmart, things are going well in many ways. Before, I always had study stress and no time for anything. Now I feel calm and confident (because of the program). I used to score a B, now I usually score an A or A+.
Hey Chris, I really want to thank you very much for developing the platform, I usually got around C for my exams, now I scored an A+, an A and a A- !!
Since using Study Smart, my average has increased significantly. I even completed a statistics course with a A+ while I'm bad at statistics. I took on extra courses this year, because of Study Smart. Thanks so much!
Ever since I started studying with StudySmart I passed all my exams !!! No more re-sits!! At first, I was happy with a pass and now I only get good grades. Many thanks!
I aced all the courses I studied with Study Smart. For law, I first scored a D, and now an A! I’m 100% sure that I’ll pass all the courses I study with Study Smart.
I always thought I studied well. My grades were fine. I could never have imagined that applying these study skills would have such a huge and direct impact on my grades, my speed and the pleasure I have in learning.
For the first time, I finally feel totally confident about the way I learn. I have the perfect overview and make great progress in terms of speed and the grades I get. Thanks, Chris!
I immediately started to enjoy learning again, and my grades soared. All of a sudden, everything went better. I highly recommend Study Smart to all students..
Being able to create my materials online made the process of studying so much smoother and quicker. I no longer have to spend a huge amount of my time on creating my summaries.
At first, my notes were a mess. Now I use Study Smart to take my notes in a perfectly structured way. It helps me to save a lot of time and do other things I enjoy.
Students that study with Study Smart get better grades. The system applies all the learning methods in such a way that both well-performing students and students who struggle perform much better.
Hi Chris, I would like to thank you very much. Last year I scored C on a course, and this year I got an A+ thanks to your method! Thank you very much!
The largest effect is that my child is more enthusiastic about school! Every parent wants their children to be happy at school, Study Smart made it happen.
In high school, I failed several exams, and that has really changed now. I actually needed this tool very much back then. Since I started studying with StudySmart, I haven't had any D's. My average score is now an A and those are results I would have never had in the past
With my old method, I passed only 3 out of 8 courses. Since I started taking my notes digitally in Study Smart, I have passed all my courses on the first try. For me, StudySmart takes away the stress of wondering if I will pass or not.
Thanks to StudySmart, I passed all my exams, and with better grades than before! On top of that, I have mastered a very good study method now, which I am confident will help me earn my degree.
How can you use the wilcoxon nonparametric test with sums of ranks?
- create the same sampling distribution, so with the prob. on y-axis
- only this time the x axis will consist of all possible sum of rankings for only one group.
- then calculate p value with the observed rank sum.
What do we do if two participants tend to have equally good ranks?
How do you get a two sided p value from a single z score?
When is it advisable to summarize a group by median instead of mean?
What is the assumption for using the median to compare groups?
When would you use the kruskal-wallis test instead of anova f?
How do you perform a kruskal wallis nonparametric test for comparing several groups?
- assumptions
- H0: identical population distributions for g groups.
- H1: population distributions not identical
- use kruskal wallis test statistic
- p value from chi squared with df=g-1
- conclusion
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
