[R] Simple question about formulae in R!?

[ONKELINX, Thierry]

Dear Johan,

Why should it be complicated? You have a very simple model, thus a very simple formula. Isn't that great?

Your formula matches the model. Though Trust~Culture + Structure * Speed_of_Integration is another option. The model fit is the same, the only difference is the parameterization of the model.

Best regards,

Thierry

ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest
team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
Kliniekstraat 25
1070 Anderlecht
Belgium
+ 32 2 525 02 51
+ 32 54 43 61 85
Thierry.Onkelinx op inbo.be
www.inbo.be

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-----Oorspronkelijk bericht-----
Van: r-help-bounces op r-project.org [mailto:r-help-bounces op r-project.org] Namens Johan Haasnoot
Verzonden: vrijdag 10 augustus 2012 9:15
Aan: r-help op r-project.org
Onderwerp: [R] Simple question about formulae in R!?

Good morning reader,



I have encountered a, probably, simple issue with respect to the *formulae* of a *regression model* I want to use in my research. I'm researching alliances as part of my study Business Economics (focus Strategy) at the Vrije Universiteit in Amsterdam. In the research model I use a moderating variable, I'm looking for confirmation or help on the formulation of the model.



The research model consist of 2 explanatory variables, a moderating variable and 1 response variable. The first explanatory variable is Culture, measured on a nominal scale and the second is Structure of the alliance, also measured on a nominal scale. The moderating variable in the relation towards Trust is Speed of Integration, measured as an interval.
The response variable is Trust, measured on a nominal scale (highly likely a 5-point Likert scale). Given the research model and the measurement scales, I intent to use a ordered probit model, often used in Marketing models,  to execute the regression modelling. I can't seem to find confirmation on how to model the formulae. I have been reading and studying R! for a couple of weeks now, read a lot of books from the R! series in the past, but I can't get a grasp on this seemingly simple formulae. I think I understand how to model multinomial regression (using the R-package MNP), how to execute a Principal Components Analysis and an Explanatory Factor analysis (obviously I'm using a questionnaire to collect my data), but the formulae itself seems to be to simple.



I expect to use the interaction symbol: "Trust~Culture + Structure :
Speed_of_Integration" for the formulae, but is it really this simple? Can anybody confirm this or help me, advise me on this issue?


Kind regards,

--

Met vriendelijke groet,

Johan Haasnoot

De Haan & Martojo
Kerklaan 5
3645 ES Vinkeveen
Telefoon: 0297-266354
Mobiel: 06-81827665
Email: johan.haasnoot op dh-m.nl
Website: www.dehaanenmartojo.nl

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