# Contributing to Theory: Independent, Mediating, Moderating and Dependent Variables

### Introduction

The course of research is a complicated and multi-dimensional process. Variables are among the fundamental constructs of a study, and the more complex the study, the more variables are employed. Bauman, Sallis, Dzewaltowski, and Owen underline that it is of ultimate significance to distinguish between determinants, correlates, mediators, moderators, and confounder variables in research. The present paper focuses on analysis of five scholarly articles encompassing use of mediating, moderating, and independent variables in order to contribute to theory in the area of concern. The outcomes of the given study are expected to contribute to theoretical background, expand comprehension of variables as core elements of research and outline the major differences and peculiarities of each kind.

## Discussion

The first scholarly article that contributes to discussion and profound comprehension of the theory on variables and their ultimate role in research is Statistical Mediation Analysis with a Multicategorical Independent Variable by Hayes and Preacher. The given study focuses on statistical mediation analysis with a multicategorical type of independent variable. To be more precise, the research aims to contribute to the theory concerning an independent variable imposing two or more conditions to a control group in an experimental study, and enhance statistical mediation analysis.

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The study by Hayes and Preacher exemplifies a simple mediation model. The given model reflects a causal sequence in which X affects Y indirectly through mediator variable M. A brief literature review aimed to outline the major achievement of the theory available also serves as a background for further study. A working example has been chosen based on the work of Kalyanaraman and Sundar. The number of participants of the given experiment was 60. The process of research and analysis had several stages, and, therefore, provided a comprehensive and diverse contribution to the field of concern. One of the major inferences from the given study relates to estimation of direct, indirect, and total effects in statistical mediation analysis. The value of the study is considerable since it will help enhance use of the aforementioned model in experimental practice and will provide more understanding in practical use of multicategorical independent variable.

The next article chosen for the present study is PROCESS: A Versatile Computational Tool for Observed Variable Mediation, Moderation, and Conditional Process Modeling by Hayes. The given article especially contributes to improvement of investigation in behavioral sciences. The main focus of the given article is PROCESS, a tool necessary for effective mediation and moderation. The vision of two-fold interaction of variables is extended by tis study. Moreover, Hayes draws a vivid and comprehensive distinction between dependent and independent variables, and underlines that use of PROCESS may result in no or low efficiency once the variables are confused or improperly used.

The author of the article relies on the theory provided by Garcia, Schmitt, Branscombe, and Ellemers. The participant of the study conducted by Hayes is 129. To be more precise, all the participants were female and provided with equal conditions and terms. The study was conducted with the purpose to demonstrate effectiveness of PROCESS and improve understanding of its peculiarities and potential challenges for the scholars. Hayesalso discusses covariates in research and their potential use for the final outcomes. An in-depth insight is made not only in moderation and mediation as separate phenomena, but also in their integration as an ultimate approach in successful research. visual support in the article by Hayes is strong and suffices to contribute significantly to the theory of concern.

One more article that will be included in the present list aimed to expand the theory on research and proper use of variables is the chapter The Use of Theory by Creswell. The given academic contribution provides a comprehensive, sufficiently itemized and proper study of diverse variables, their role in research and peculiarities of empirical use in the studies. Moreover, the study distinguishes between qualitative and quantitative types of research which is crucially important when choosing and managing variables. This work is a guide to research with properly selected and coordinated variables, not an experimental study which contributes to expansion of the theory in question. Its significance is in systematic review of variables, their major aim and research potential.

The next article that has made a valuable contribution to the currently discussed theory is Conceptual Analysis of Moderator and Mediator Variables in Business Research. The study focuses of moderating and mediating variables which are employed in business research. As the authors of the article underline, to provide specific implications, Kang et al. model with respect to Balanced Scorecard technique is conceptually extended. Extension of the given theory is supported not only by analysis of distinctions and core aspects of each variable, but also about the potential of Mediated-Moderation and Moderated-Mediation designs as well as their effect on business research. The given study complements the article by Hayes, and provides a profound understanding of mediation and moderation during investigative process.

The currently discussed article by Namazi and Namazi  is of ultimately significant value to the field of interest as far as it for first time, explored characteristics, distinctions and significance of the moderating, mediating, mediated-moderation and moderated-mediation effects of business research by extending Katz et al.  model on a Balanced Scorecard perspective. The core conclusion of the study is that preceding variables have significant influence on conceptual theories and research design. Hence, the expected outcomes may also be altered and improved in terms of quality and relevance to the field of concern. The paper presents a thorough and itemized analysis of the currently conducted business research which means a solid contribution to the theory taking into account evident gaps in presently available knowledge in this area. The given gap is connected with ambiguity in operationalization of the effects triggered by moderating and mediating variables in business empirical studies. Furthermore, the study by Namazi and Namazi is a proper basis for further in-depth insight into effects of control and extraneous variables. One more serious gap in the knowledge in the scope of interest is integration process between moderation and mediation. The currently discussed studies contribute to its elimination.

Finally, the article Mediation Analysis Allowing for ExposureMediator Interactions and Causal Interpretation: Theoretical Assumptions and Implementation with SAS and SPSS Macros by Valeri and Vander Weele. The study contributes to enhancement of the approach of mediation analysis in social, biomedical and psychological disciplines on the current stage of development. Furthermore, this work encompasses all the gaps and extends the accomplishments of scholarly works by VanderWeele and Vansteelandt. The gaps of the aforementioned studies included dichotomous mediation and count outcomes. Furthermore, the study provides a significant empirical contribution to the field of concern via development of the macros to SAS and SPSS aimed to automatize mediation analysis techniques.

The article by Valeri and VanderWeele discusses and compares different approaches to mediation analysis and provides numerous examples as well as step by step algorithm of proper SAS and SPSS use. Such an empirical study has a significant value since it systematizes the knowledge that has been already acquired by the scholars and offers macros for use of statistical tools. Diversity and detailed explanations of examples are provided by the authors for further comprehension of the analysis process.

A study involving mediator and or moderator variables that can contribute to theory of concern should be based on the up-to-date academic sources and focus on the major gaps. As it is evident from the above presented review and analysis of the articles, the core gaps include Mediated-Moderation and Moderated-Mediation designs, their integration and proper use of dichotomous variable. Hence, the study should cover one of these issues and conduct an extensive empirical study. The study should also focus on controversies related to the currently discussed variables since they often provoke major problematic issues, errors and deficit of accuracy. Finally, the future study is expected to contribute to statistical analysis tools and their proper use by the scholars.

### Conclusion

Thus, the area of research is multidimensional and has numerous challenges and gaps in knowledge. The present study aimed to contribute to expansion of understanding of role, potential and drawbacks of independent, moderating and mediating variables. Five up-to-date scholarly sources employed as a background provided in-depth insight into particular gaps, their significance and opportunity for their improvement. The most serious challenge is imposed by the integration of Mediated-Moderation and Moderated-Mediation designs in the course of research. All the scholars focused on the given issue with particular concern. Moreover, proper use of tools aimed to conduct statistical analysis was also addressed, and SAS, PROCESS and SPSS were used for illustration of efficient and constructive research performance. The study recommended for further investigation of the discussed field of interest was described in details.