Simple Question, Not So Simple Answer: Interpreting Interaction Terms in Moderated Multiple Regression

1994 ◽  
Vol 20 (1) ◽  
pp. 159-165 ◽  
Author(s):  
Arthur G. Bedeian ◽  
Kevin W. Mossholder
Keyword(s):  
Multiple Regression ◽  
Significant Interaction ◽  
A Priori ◽  
Moderated Multiple Regression ◽  
Statistical Comparison ◽  
Interaction Terms ◽  
Simple Question ◽  
Interaction Term ◽  
Significant Interaction Term

The appropriate interpretation of interaction terms in studies employing moderated multiple regression ( MMR) analysis is considered. It is argued that given a theory-based, a priori hypothesis, an MMR analysis is analogous to a planned statistical comparison and, thus, a significant overall F value is not a prerequisite for interpreting a significant interaction term.

Retention of Connected Discourse

1969 ◽  
Vol 24 (1) ◽  
pp. 31-34 ◽  
Author(s):  
John A. Mills ◽  
Gordon Winocur
Keyword(s):  
Retention Interval ◽  
Associative Strength ◽  
Significant Interaction ◽  
Interaction Terms ◽  
Connected Discourse ◽  
Main Effect ◽  
Interaction Term ◽  
Retention Intervals ◽  
Main Effects

6 24-word English sentences were made up, 2 representing each of 3 levels of meaningfulness. Meaningfulness was defined in terms of the Thorndike-Lorge frequency of the words making up the sentences. The sentences were mounted on memory drums and learned by serial anticipation to a criterion of 100% correct responses or to a lower criterion, equivalent across level of meaningfulness. The retention intervals were 20 min. and 24 hr., the former providing a control for post-criterial drop. The measure of retention was the number of items lost during the interval. The main effects for both retention interval and meaningfulness were significant as was the interaction term between level of learning and retention interval. Because there were no significant interaction terms involving meaningfulness, it was concluded that the main effect for meaningfulness was an artifact resulting from differing degrees of associative strength at the end of learning. This conclusion was reinforced by scrutiny of 24-hr. loss scores, corrected for post-criterial drop.

scholarly journals Effects of Aspen and Spruce Density on Size and Number of Lower Branches 20 Years after Thinning of Two Boreal Mixedwood Stands

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 211
Author(s):  
Philip G. Comeau
Keyword(s):  
Significant Interaction ◽  
Wood Quality ◽  
Branch Diameter ◽  
Breast Height ◽  
Crown Width ◽  
Interaction Term ◽  
Study Sites ◽  
Branch Size ◽  
Significant Interaction Term ◽  
Number Of Branches

This study examined branch diameter, number of whorls, and number of branches in the lower 2 m of the stems of white spruce growing in pure stands and in mixture with a range of densities of trembling aspen. Data were collected from two study sites located north of Big River Saskatchewan, which were regenerated following clearcutting in 1992 and thinned in 1996 to five aspen densities and two spruce densities. Results show significant decreases in spruce diameter at breast height (DBH), height, live crown ratio, maximum branch diameter in the lower 2 m, average branch diameter in the whorl closest to 1 m, and increases in tree slenderness with increases in aspen density. Increasing spruce density reduced the number of live branches and number of live branch whorls in the lower 2 m. Maximum branch diameter in the whorl closest to 1 m was influenced by both aspen and spruce density, with a significant interaction term resulting from effects of intraspecific competition being evident for aspen densities of 1500 stems ha−1 or lower. DBH and slenderness explained more than 49% of the variation in spruce crown width, maximum branch diameter in the lower 2 m, maximum live branch diameter in the whorl closest to 1 m, and average live branch diameter in the whorl closest to 1 m. DBH explained more variation in crown width and branch diameter than slenderness. This study demonstrates that growing spruce in mixture with aspen can lead to reductions in branch size and that early thinning to low aspen densities could lead to increases in size of knots and associated reductions in wood quality, particularly when spruce densities are low.

scholarly journals Cardiorespiratory Fitness and Muscular Strength Moderates the Relationship between FNDC5 Polymorphism and Adiposity in Children and Adolescents

2021 ◽  
Vol 18 (18) ◽  
pp. 9797
Author(s):  
Pâmela Ferreira Todendi ◽  
Caroline Brand ◽  
João Francisco de Castro Silveira ◽  
Ryan Donald Burns ◽  
J. Alfredo Martínez ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Cardiorespiratory Fitness ◽  
Skin Color ◽  
Significant Interaction ◽  
Muscular Strength ◽  
School Type ◽  
Interaction Term ◽  
The Relationship ◽  
Significant Interaction Term

The human locus FNDC5 rs16835198 contributes positively to anthropometric phenotypes in children and adolescents. However, the role of specific components of physical fitness in this relationship is not known. The present study aimed to verify the moderator role of cardiorespiratory fitness (CRF) and muscular strength in the relationship between rs16835198 polymorphism FNDC5 and adiposity in children and adolescents. This cross-sectional study was carried out by genotyping the rs16835198 FNDC5 polymorphism in 1701 children and adolescents (mean age 11.73 ± 2.75 years). Obesity was assessed using waist circumference and body mass index (BMI) z-scores. To evaluate CRF and muscular strength, the 6 min run/walk test and lower limb strength (LLS) were used. Linear regression models were applied, and all analyses were adjusted for age, sex, skin color, living area, and school type. A significant interaction term for CRF (p = 0.038) and LLS (p = 0.040) × rs16835198 FNDC5 with WC was identified. Regarding BMI, a significant interaction term for CRF (p = 0.007) and LLS (p = 0.044) × rs16835198 FNDC5 was observed. Moreover, medium and high CRF and LLS levels protected against higher WC and BMI. In conclusion, adiposity levels of children and adolescents with a genetic predisposition to obesity might be modified by improving CRF and muscular strength.

scholarly journals 312 Female sex independently predicts adjuvant immunotherapeutic benefit from CTLA4 immune checkpoint inhibition

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A339-A339
Author(s):  
Ahmad Tarhini ◽  
Ni Kang ◽  
Sandra Lee ◽  
F Stephen Hodi ◽  
Gary Cohen ◽  
...  
Keyword(s):  
Overall Survival ◽  
Treatment Efficacy ◽  
Significant Interaction ◽  
Cox Regression ◽  
Performance Status ◽  
Phase Iii ◽  
High Dose ◽  
List Type ◽  
Female Sex ◽  
Interaction Term

BackgroundSex differences in tumor immunity and response to immunotherapy were shown in murine models and descriptive analyses from recent clinical trials. Female sex hormones have been implicated in melanoma development and response to systemic therapy. We hypothesized a gender difference in response to adjuvant immunotherapy with ipilimumab (3 or 10 mg/kg; ipi3 or ipi10) versus high dose IFNα (HDI) as tested in the E1609 trial.MethodsE1609 demonstrated significant overall survival (OS) benefit with ipi3 versus HDI.1 We investigated treatment efficacy between ipi and HDI in the subgroups by sex (female, male), age (< 55 or ≥55), stage at study entry (IIIB, IIIC, M1a/1b), ECOG performance status (PS 0, 1), ulceration (yes, no), primary tumor (known, unknown), number of lymph nodes involved (0, 1, 2–3, 4+). Forest plots were created to compare OS and RFS with ipi3 vs. HDI and ipi10 vs. HDI using the concurrently randomized ITT populations. For the estimated HRs, 95% confidence intervals were created for all subgroups.ResultsThe subgroups of female, stage IIIC, PS=1, ulcerated, in-transit without lymph node involvement demonstrated significant improvement in overall survival (OS) and/or relapse free survival (RFS) with ipi3 versus HDI as summarized in table 1. Female sex was significant for both OS and RFS and was further explored. In investigating RFS with ipi3 versus HDI, a multivariate Cox regression model including sex, treatment and interaction term of sex*treatment, indicated a significant interaction between sex and treatment (P = 0.026). Including sex, PS (0 vs. 1), age (<55 vs. 55+), ulceration (yes vs. no), stage (IIIB, IIIC, M1a, M1b), treatment and interaction term of sex*treatment, indicated a significant interaction between sex and treatment (P = 0.024). While similar trends were seen, no significant interactions between sex and treatment effect were found in the OS multivariate analysis or in the comparison of ipi10 versus HDI. When exploring age, in the univariate analyses in the ipi3 versus HDI comparison older women appeared to drive most of the difference (age ≥55: OS, P=0.02 and RFS, P=0.08; differences non-significant for women <55). Table 1.Abstract 312 Table 1Treatment efficacy between ipi3 and HDI by subgroupConclusionsFemale sex was independently associated with RFS adjuvant immunotherapeutic benefit from ipi3, supporting a potentially important role for female related factors in the immune response against melanoma, and these warrant further investigation.Trial RegistrationNCT01274338Ethics ApprovalThe study protocol was approved by the institutional review board (IRB) of each participating institution and conducted in accordance with Good Clinical Practice guidelines as defined by the International Conference on Harmonisation. This study was monitored by the ECOG-ACRIN DataSafety Monitoring Committee and the NCI.ConsentAll patients provided IRB-approved written informed consent.ReferenceTarhini AA, Lee SJ, Hodi FS, Rao UNM, Cohen GI, Hamid O, Hutchins LF, Sosman JA, Kluger HM, Eroglu Z, Koon HB, Lawrence DP, Kendra KL, Minor DR, Lee CB, Albertini MR, Flaherty LE, Petrella TM, Streicher H, Sondak VK, Kirkwood JM. Phase III Study of Adjuvant Ipilimumab (3 or 10 mg/kg) Versus High-Dose Interferon Alfa-2b for Resected High-Risk Melanoma: North American Intergroup E1609. J Clin Oncol. 2020 Feb 20;38(6):567–575. PMID: 31880964.

Interpreting moderated multiple regression: A comment on Van Iddekinge, Aguinis, Mackey, and DeOrtentiis (2018).

2021 ◽  
Vol 106 (3) ◽  
pp. 467-475
Author(s):  
Jeffrey B. Vancouver ◽  
Bruce W. Carlson ◽  
Lindsay Y. Dhanani ◽  
Cassandra E. Colton
Keyword(s):  
Multiple Regression ◽  
Moderated Multiple Regression

Evaluating Equity in the Marital Relationship: An Alternative Approach

1982 ◽  
Vol 51 (3) ◽  
pp. 759-762 ◽  
Author(s):  
Walter R. Schumm ◽  
Julia E. Kirn
Keyword(s):  
Regression Analysis ◽  
Statistical Analysis ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Careful Attention ◽  
Social Scientists ◽  
Difference Scores ◽  
Interaction Terms ◽  
Integrate Theory ◽  
Alternative Approach

Theory concerning the differing perceptions of marital partners often seems to invite the use of difference scores for measuring concepts such as equity, homogamy, inconsistency in social status, consensus regarding various attitudes, and similarity of personality traits. However, as illustrated with an example from equity theory, difference scores should be replaced by interaction terms in multiple regression analysis to evaluate such theory adequately. More careful attention needs to be paid to how family social scientists integrate theory, measurement, and statistical analysis in research.

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