Forced choice (a or b) locus of control scale-ordinal or interval?

Posted by Basia on Oct 01, 2014; 2:56am
URL: http://spssx-discussion.165.s1.nabble.com/Forced-choice-a-or-b-locus-of-control-scale-ordinal-or-interval-tp5727458.html

Hi,
I need to identify level of measurement for a locus of control scale (Rotter Internal External Locus of Control Scale) which is a 29 item forced choice (select answer a or b) self-report scale with the scoring that range from 0(internality) to 23 (externality). I's struggling identifying the level of measurement. Is it ordinal or interval? I'm thinking it's more internal due to arbitrary 0. Could anyone help and explain this to me?

Thank you!
Basia