Research methodology
Application of Path Analysis and Structural Equation Modeling in Nutrition and Dietetics
This is one of a series of monographs on research design and analysis. The purpose of this article is to describe a set of statistical procedures or techniques used to develop and test structural models that characterize the relationships and interrelationships between a group of concepts and variables. These procedures include multiple regression, exploratory and confirmatory factor analysis, path analysis, and structural equation modeling. The article describes the purpose of each of these procedures and how they relate to and build on one another.Pointers and Pitfalls in Interpreting Nutrition and Dietetics Research: The Importance of Statistical and Clinical Significance
This monograph focuses on understanding statistical and clinical significance and is one in a research and statistics series published by the statistical team of the Journal of the Academy of Nutrition and Dietetics. The content covers the research questions, definition of clinical significance, hypothesis testing, P values, effect sizes, sample sizes, CIs, power analyses, minimal clinically important differences, and validity. This monograph concludes with a summary of the importance of clinical and statistical results for credentialed nutrition and dietetics practitioners to consider when assessing statistical and clinical significance.Crossover Designs in Nutrition and Dietetics Research
This article is the 12th installment in a statistical series exploring the importance of research design, epidemiologic methods, and statistical analysis as applied to nutrition and dietetics research. The purpose of this series is to assist registered dietitian nutritionists in interpreting nutrition research and aid nutrition researchers in applying scientific principles to produce high-quality nutrition research. This article focuses on the use of crossover designs in nutrition and dietetics research.Mixed-Methods Research in Nutrition and Dietetics
This work focuses on mixed-methods research (MMR) and is the 11th in a series exploring the importance of research design, statistical analysis, and epidemiologic methods as applied to nutrition and dietetics research. MMR research is an investigative technique that applies both quantitative and qualitative data. The purpose of this article is to define MMR; describe its history and nature; provide reasons for its use; describe and explain the six different MMR designs; describe sample selection; and provide guidance in data collection, analysis, and inference.Publishing Nutrition Research: A Review of Multivariate Techniques—Part 3: Data Reduction Methods
This is the ninth in a series of monographs on research design and analysis, and the third in a set of these monographs devoted to multivariate methods. The purpose of this article is to provide an overview of data reduction methods, including principal components analysis, factor analysis, reduced rank regression, and cluster analysis. In the field of nutrition, data reduction methods can be used for three general purposes: for descriptive analysis in which large sets of variables are efficiently summarized, to create variables to be used in subsequent analysis and hypothesis testing, and in questionnaire development.Publishing Nutrition Research: A Review of Multivariate Techniques—Part 2: Analysis of Variance
This article is the eighth in a series exploring the importance of research design, statistical analysis, and epidemiology in nutrition and dietetics research, and the second in a series focused on multivariate statistical analytical techniques. The purpose of this review is to examine the statistical technique, analysis of variance (ANOVA), from its simplest to multivariate applications. Many dietetics practitioners are familiar with basic ANOVA, but less informed of the multivariate applications such as multiway ANOVA, repeated-measures ANOVA, analysis of covariance, multiple ANOVA, and multiple analysis of covariance.An Introduction to Qualitative Research for Food and Nutrition Professionals
The purpose of this article is to define qualitative research, explain its design, explore its congruence with quantitative research, and provide examples of its applications in dietetics. Also, methods to ensure validity, reliability, and relevance are addressed. Readers will gain increased knowledge about qualitative research and greater competency in evaluating this type of research. The hope is that food and nutrition professionals will be inspired to conduct and publish qualitative research, adding to the body of peer-reviewed dietetics-related qualitative publications.Publishing Nutrition Research: A Review of Nonparametric Methods, Part 3
This is the third article in a periodic five-part series on publishing nutrition research. These monographs are designed to assist in the interpretation of the Journal of the American Dietetic Association author guidelines and provide guidance in publishing and interpreting nutrition-related research articles. This installment focuses on the use of nonparametric statistical methods. The rationale for their use, their advantages and disadvantages, nonparametric alternatives to parametric tests, nonparametric statistical analysis, examples of their use, and helpful resources for further study are topics and issues addressed in this article.
