Hello everyone, Recently, I faced a problem on explanatory of *Interaction variable* in Linear Regression, could anyone give me some help on how to explain that?
the response variable Y is significantly correlated with *Interaction variable X* which is consisted of Continuous predictor A and Categorical predictor B. The Categorical predictor B has two factors B1 (value=1) and B2 (value=0). The result is as follows: Call: lm(formula = Y ~ ... + *A:B*, data = ..., na.action = na.omit) Residuals: Min 1Q Median 3Q Max -0.84267 -0.29877 0.01961 0.32187 0.98519 Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 0.7699265 0.5129588 1.501 0.1408 BB1 -0.6657700 0.2668956 -2.494 0.0166 * A 0.0017799 0.0007569 2.352 0.0235 * ... 0.2393929 0.2334615 1.025 0.3110 ... -0.3877065 0.2317213 -1.673 0.1017 *BB1:A 0.0059008 0.0025522 2.312 0.0257 ** --- Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 Residual standard error: 0.4379 on 42 degrees of freedom Multiple R-squared: 0.2813, Adjusted R-squared: 0.1958 F-statistic: 3.288 on 5 and 42 DF, p-value: 0.01354 *My questions:* 1. *How to explain the result of BB1:A correlated with Y? since BB1 is only one factor of B, and if it is combined with A, how does the combination mean?* 2. *Can I believe the significance of either single BB1 or A? Why?* Thank you in advance for any possible help! Chen, a beginner in R and statistics -- Chen Xiu Guest Fellow/ PhD Student Department of Conservation Biology UFZ - Helmholtz Centre for Environmental Research Permoserstr. 15 D-04318 Leipzig Germany [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.