The effects of third variables in psychological research
AbstractGiven a causal relationship between an independent variable (X) and a response variable (Y), the interest of some applied researchers is sometimes focused on knowing the role playing for alternative intervening variables (third variables or Z-variables), and particularly the role of mediating and moderating variables. Some influential works have repeatedly denounced that in applied psychology some confusion exists with respect to the meaning and appropriate use of third variables effects as causal hypotheses. This work is intended to reinforce the comprehension and using of five of more known effects of third variables and concretely the effects of covariation, spuriousness or confounding, suppression, and particularly of mediation and moderation, with special attention towards the application of statistical tests and the report of most common mistakes that usually appear when we tackle a causal analysis. An accessible language for applied researcher with path diagrams is used. A flow diagram is finally proposed in order to help applied researchers to distinguish between third variable effects and to make easier the application of the appropriate statistical procedures.
Copyright (c) 1970 Servicio de Publicaciones de la Universidad de Murcia
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
The works published in this journal are subject to the following terms:
1. The Publications Service of the University of Murcia (the publisher) retains the property rights (copyright) of published works, and encourages and enables the reuse of the same under the license specified in paragraph 2.
2. The works are published in the online edition of the journal under a Creative Commons Attribution-NonCommercial 4.0 (legal text). You can copy, use, distribute, transmit and publicly display, provided that: i) you cite the author and the original source of publication (journal, editorial and URL of the work), ii) are not used for commercial purposes, iii ) mentions the existence and specifications of this license.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
3. Conditions of self-archiving. Is allowed and encouraged the authors to disseminate electronically pre-print versions (version before being evaluated and sent to the journal) and / or post-print (version reviewed and accepted for publication) of their works before publication, as it encourages its earliest circulation and diffusion and thus a possible increase in its citation and scope between the academic community. RoMEO Color: Green.