stats defs anyone?

March 18, 2009 5:52 PM

If anyone could be bothered helping me out with 4 definitions relating to psychology/statistics I would be so, so very grateful. I have searched and searched google and cannot find definitions for the following- Rule of assignment, Permissible transformations, Permissible arithmetic operations, Permissible statistics. I have a very vague idea of what they mean but would LOVE to have some working definitions.
posted by beccyjoe to Education (2 answers total)

Permissible arithmetic operations just refers to what sorts of operations you can use with what sorts of data. There are four major categories of data:

1 - Nominal: These are categories with not actual numerical properties. 1 = Republican, 2 = Democrat

2 - Ordinal: These have the quality of "higher" and "lower" but not in a uniform way. Think of 5-point Likert-type scales and things like that.

3 - Interval: True numerical relationships among values, but no true zero point. Think of temperature. The zero is really without meaning - but the relationships among the numbers make sense.

4 - Ratio: True numerical relationships and true zero values. Think of length or depth. The zero values make sense.

Permissible arithmetic operations are the rules that govern what can be done with each of these categories. For example, you can average Interval and Ratio data, but you can't average Ordinal or Nominal data. You can add and subtract Ordinal data, but you can't add or subtract Nominal data. And so on.

If you know this stuff, you'll find that people commit errors of permissible operations ALL THE TIME! It's on the news and elsewhere constantly.

I think Permissible Statistics and Permissible Transformations might be very similar concepts, but I haven't actually heard those terms.
posted by crapples at 7:16 PM on March 18, 2009

Response by poster: thanks crapples. yes, hal_c_on it is to do with the four sorts of data that crapples listed and how you can compute the various data...
posted by beccyjoe at 7:41 PM on March 18, 2009