cumulative link model in R

General
1

Hi!
I'm new to R for my thesis and I tried to understand the basics of R and statistics with 'how to' youtube videos.
I need to test if there are correlations between ordinal data (questionnaires with scoring systems, one of them a likert-scale).
My promotor said something about a cumulative link model, sadly I never heard about that before and I don't really find info about it on the internet...
Is their somebody who can explain why you should use this function in this case?

I post some data below...

Sub Groep Niet_Behandeling 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17
1    1    BE                1   2   1   4   2   1   3   3   4   1    1    1    1    1    1    1    3    1
2   23    BE                1   2   4   2   1   1   1   2   4   1    1    1    1    5    1    1    1    1
3   24    BE                1   1   4   2   1   1   1   1   1   1    1    1    1    1    1    1    1    1
4   25  BEBD                1   2   2   4   2   2   2   4   4   3    3    3    3    3    3    3    3    3
5   27    BE                1   2   3   4   1   3   4   1   4   2    4    1    1    1    1    1    1    1
6   32  BEBD                1   1   4   2   4   1   4   1   4   1    5    1    3    1    1    1    1    1
7   34    BE                1   2   5   4   4   4   3   4   4   4    3    3    3    3    2    1    3    3
8   37    BE                1   3   3   4   2   1   3   2   2   3    1    1    1    3    1    1    1    1
9   38    BE                1   4   5   1   3   2   4   4   4   1    1    3    2    1    1    1    4    4
10  41    BE                1   3   3   3   2   2   4   4   3   2    2    2    2    2    1    1    1    1
11  45    BE                1   1   5   3   3   1   2   4   5   3    2    2    3    2    2    1    4    3
12  55  BEBD                1   1   1   1   1   1   3   2   4   1    4    1    1    5    1    1    1    1
13  58    BE                1   4   3   4   2   3   2   2   3   1    2    1    3    2    1    1    2    1
14  65  BEBD                1   4   2   5   1   1   3   2   3   1    1    1    1    1    1    1    1    1
15  66    BE                1   4   5   4   2   1   2   3   2   1    1    1    1    1    1    1    1    1
16  68    BE                1   4   2   4   5   3   4   4   3   2    2    2    2    2    1    1    2    2
17  72  BEBD                1   4   2   5   1   1   1   1   3   1    1    1    1    1    1    1    2    1
18  73  BEBD                1   4   2   4   3   2   2   2   4   1    2    2    1    2    1    1    2    1

      2.18 2.19 2.20 2.21 2.22 EDE_Q_EC EDE_R EDE-Q_WC EDE_Q_SC EDE_Q_Totaal
1     3    4    3    5    3       24    28       30       30          132
2     4    1    1    2    4        5    10        8       13           39
3     4    3    2    1    1       23    28       30       48          129
4     4    4    3    4    3       22    17       48       30          117
5     1    1    1    2    1       23    17       29       47          120
6     1    1    4    2    1       10     2       16       34           66
7     3    3    3    4    3       17     6       27       45           95
8     1    1    1    3    3        4     3       18       35           62
9     5    4    4    1    1       16    10       29       48          103
10    1    1    1    1    1        4     4        2        5           17
11    3    5    4    4    3       19    12       25       40           97
12    1    3    1    5    1       19    27       30       48          126
13    1    1    3    4    3       11    14       25       38           91
14    1    2    3    5    3       17    11       21       38           92
15    2    2    1    5    3        7    15       13       28           68
16    3    4    4    5    1       15    18       27       43          106
17    1    1    1    4    3        4    15       14       13           49
18    1    3    2    5    3        4     3       11       22           42
2

I tapped my knowledge base (google) and the first hit on Cumulative link model is the R package CLM article in PDF format

3

The cumulative link model is a type of ordinal regression. Here are notes from a short course by Alan Agresti, author of the text Analysis of Ordinal Categorical Data (Agresti has published other R examples for ordinal regression, as well (here and here, for example)).

A google search for ordinal regression in R turns up many tutorials. There are also a number of tutorials on bayesian ordinal regression models in R.

4

You might consider looking at a simple Chi-squared test of independence to learn more about your data before moving on to regression