All Questions
10
questions
3
votes
1
answer
695
views
I have applied many statistical tests to my data, but still cannot determine normality
I have run multiple tests to determine normality on my dataset, but I am unsure which one to adhere to, especially since my histograms, density plots, and QQ plots leave much to be desired in terms of ...
- 53
1
vote
0
answers
286
views
Testing for normality with small sample sizes in order to use t-test [duplicate]
I run into a conundrum when determining whether a small sample is appropriate for a t-test. I know that if I meet the assumptions, a t-test produces approximately correct inference with any sample ...
- 497
2
votes
1
answer
5k
views
Paired t-test of a non-normal data with sample size 66
I have a paired data with n=66. I understand that normality condition of differences data should be met to conduct a paired t-test. However, from the histogram, it doesn't appear so normal. The p-...
- 135
1
vote
1
answer
226
views
Should I use non-parametric tests?
I am a teacher working on a simple research with the aim of studying whether the set of lesson designs I created can improve student performance. I have two groups with 15 students each. I divided ...
7
votes
2
answers
12k
views
Non-Parametric altervative to one sample t-test
I have a the following hypothesis: $H_0: \mu=4$, $H_1: \mu\neq 4$, which I wanted to test using a one sample t-test.
However, my data is not normally distributed and a transformation was not found. ...
- 486
6
votes
2
answers
370
views
What is an example of data where the permutation test succeeds but a normal t-test fails?
In literature, I normally see authors use a two sample permutation test on normal data to show that it works as well as the two sample t-test. However, the real power for permutation tests should be ...
- 2,107
1
vote
1
answer
138
views
Total scores are normally distributed, but subtest scores are not; what to do?
I have two sets of data for males and females: $n=33$. I'd like to compare test results for both groups. I want to do a $t$ test, and I know my data should be normally distributed if I want to use a ...
- 231
0
votes
2
answers
2k
views
Absolute values -- parametric or non-parametric test?
I am looking at the absolute difference in values between pairs of numbers. I am then comparing these absolute values between two groups (e.g. Males and Females). Since these are absolute values I ...
- 1
0
votes
1
answer
2k
views
What statistical test to use for my questionnaire
I have to do some statistical tests on a questionnaire and don't know which tests i need to do. The questionnaire have been marked as right or wrong and I have about 60 peoples results. The tests i ...
1
vote
1
answer
262
views
All my observations are identical. Use a non-parametric test?
I was doing test for normality on variables and came across one that had identical values for each observation. I can't do a normality test. I plotted the kernel density and it looks normal, however ...
- 157