Recent content by blubblub

  1. B

    A coincidence isn't that unlikely?

    Thanks for the fast reply. Glad that my reasoning wasn't flawed, since I know how tricky probability can become :-) Is there a name for this kind of fallacy(?) where you forget to take into consideration the sample space?
  2. B

    A coincidence isn't that unlikely?

    A few days ago I had a brain thought. Often you hear people say if something unlikely occurs 'what are the chances'. Or in case something really unlikely occurs that it is almost a miracle. I'll use the word 'miracle' here just for a lack of a better word (I'm not a native speaker), not so much...
  3. B

    Friedman post hoc Conover - 2 formulas?

    I'm trying to figure out the post-hoc procedure from Conover for a Friedman test. Unfortunately I do not have a copy of the original book 'Practical Nonparametric Statistics' and it seems a bit expensive. So I've been googling and came across two different formula's both claiming to have Conover...
  4. B

    Why normality assumption needed?

    I often see that for parametric tests one assumption is that the population should be normally distributed. However if I understand correctly the central limit theory shows that the distribution of the sample means (the sampling distribution) has a normal distribution, irrespective of the...
  5. B

    Example(s) of an interval scale

    Temperature in Fahrenheit or Celsius is almost always used as the example of an interval scale. Another one is Year (e.g. birth year) although one could argue that not every year has the same amount of days and therefor the difference between two consecutive years is not exactly the same. The...
  6. B

    measurement level of exponential temperature in degrees Celsius

    I was wondering about the following theoretical example. Assume that I have measured temperature in degrees Celsius on various days (x), and for some strange reason converted each of these using e^x. My question is now, what measurement level is this 'exponential temperature'? My own...
  7. B

    one sample median test for a Likert item?

    Today I was trying to figure out which test would be appropriate if you have an ordinal variable and want to test if the median could be equal to a given value. The ordinal variable is on a discrete scale ranging from 1 to 5. For example 20 students are asked to if they 1=fully disagree...
  8. B

    McNemar test and all the variations, is mid-p indeed the best?

    After a long search I think I finally got this right, but would like to know for sure. I've been trying to sort out all the variations on the McNemar test. What I've found so far: McNemar test as proposed by McNemar himself in 1947 uses a chi-square distribution. As such a continuity...
  9. B

    Differences in responses on a 5 point scale between three groups? Kruskal-Wallis?

    Dear madam/sir, Recently I have designed a course that was run at three different locations. To know what the students thought of the course they were given the same questionnaire on all three locations. One of the questions as an example was to indicate the extend to which they agreed with the...