I have some diffuclty assessing the level of measurement of these two variables... When time spent reading a book has been measured with the categories 0 (=never), 0.5 (about 1 hour), 1.5 (about 2 hours), 2.5 (about 2 - 3 hours), 3.5 (more than 3 hours). I would say this an ordinal / categorical measure, due the unequal differences in values!

The second variable is amount of close friends: 0, 1, 2 or 3 (which indicates 3 or more). I would say this is also an example of a categorical measure!

Is it allowed to use the first variable as independent variable in a regression analysis?

Is it allowed to use the second variable as dependent variable in a regression analysis

Thanks in advance!