# test with multiple independent and dependent variables

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## test with multiple independent and dependent variables

 Hey, For my research I have multiple independent and multiple dependent variables (and some covariates). One independent variable has four categories while the others are continuous. The dependent variables are all continuous. I think the covariates should be continuous but apart from continuous variables I also want to test for the effect of categorical variables like gender and employment status (how should I do this?) My guess was to try MANCOVA, so I did this with the independent variable and the 4 groups, and the dependent variables + covariates. It worked (except that I don't know if it is appropriate to put gender and employment status etc. under covariates). I then added the continuous independent variables to the test, but it didn't work (some warning that it was too much). - How can I deal with gender and employment status? - Should I use a different test for the analyses, or just for analysing the effect of the continuous independent variables on the dependent ones? Thank you!! -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

You can use a multiple regression approach dummy coding the categorical independent variables. Covariates are entered as blocks, as in a heirarchical multiple regression. There's a tutorial at:

http://bayes.acs.unt.edu:8083/BayesContent/class/Jon/SPSS_SC/Module9/M9_Regression/SPSS_M9_Regression3.htm

Brian

From: SPSSX(r) Discussion <[hidden email]> on behalf of spssdummy <[hidden email]>
Sent: Monday, June 10, 2019 11:21:34 AM
To: [hidden email]
Subject: test with multiple independent and dependent variables

Hey,
For my research I have multiple independent and multiple dependent variables
(and some covariates). One independent variable has four categories while
the others are continuous. The dependent variables are all continuous. I
think the covariates should be continuous but apart from continuous
variables I also want to test for the effect of categorical variables like
gender and employment status (how should I do this?)

My guess was to try MANCOVA, so I did this with the independent variable and
the 4 groups, and the dependent variables + covariates. It worked (except
that I don't know if it is appropriate to put gender and employment status
etc. under covariates). I then added the continuous independent variables to
the test, but it didn't work (some warning that it was too much).

- How can I deal with gender and employment status?
- Should I use a different test for the analyses, or just for analysing the
effect of the continuous independent variables on the dependent ones?

Thank you!!

--
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## Re: test with multiple independent and dependent variables

 Thanks Brian! Very useful tutorial. The only thing is that this is suitable for just one dependent variable at a time right? So should I do the same multiple regression analysis multiple times as I have multiple dependent variables? Second, my independent categorical variable has number 1, 2, 3 and 4 right now. Is this okay for the analyses? Thanks again -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

 Your 4-category independent variable is fine. It will require three dummy variables. You'll probably need to look up how to dummy code multiple-category variables if you don't know how at this time. Multiple regression is made for one dependent variable. There is an alternative called canonical correlation (notice the term correlation connoting that you cannot attribute independence/dependence). Canonical correlation finds the best set of variables in set A (e.g., your independent variables) to the best in set B (e.g., your dependent variables). So basically, you have the correlation between one composite variable and another composite variable. Canonical correlation is a real bear to interpret. I'd stick with one dependent at a time. Brian From: SPSSX(r) Discussion <[hidden email]> on behalf of spssdummy <[hidden email]> Sent: Monday, June 10, 2019 2:41:59 PM To: [hidden email] Subject: Re: test with multiple independent and dependent variables   Thanks Brian! Very useful tutorial. The only thing is that this is suitable for just one dependent variable at a time right? So should I do the same multiple regression analysis multiple times as I have multiple dependent variables? Second, my independent categorical variable has number 1, 2, 3 and 4 right now. Is this okay for the analyses? Thanks again -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/ ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

 For creating a set of dummy variables from a categorical variable, check out the SPSSINC CREATE DUMMIES extension command installable from the Extensions > Extension Hub menu.Â  It will appear on the Transform menu once installed.If you do want to venture into canonical correlations, there are several ways to get them in Statistics, but the easiest is probably the STATS CANCORR extension command, also installable from the Extension Hub.On Mon, Jun 10, 2019 at 12:53 PM Dates, Brian <[hidden email]> wrote: Your 4-category independent variable is fine. It will require three dummy variables. You'll probably need to look up how to dummy code multiple-category variables if you don't know how at this time. Multiple regression is made for one dependent variable. There is an alternative called canonical correlation (notice the term correlation connoting that you cannot attribute independence/dependence). Canonical correlation finds the best set of variables in set A (e.g., your independent variables) to the best in set B (e.g., your dependent variables). So basically, you have the correlation between one composite variable and another composite variable.Â Canonical correlation is a real bear to interpret. I'd stick with one dependent at a time. Brian From: SPSSX(r) Discussion <[hidden email]> on behalf of spssdummy <[hidden email]> Sent: Monday, June 10, 2019 2:41:59 PM To: [hidden email] Subject: Re: test with multiple independent and dependent variables Â  Thanks Brian! Very useful tutorial. The only thing is that this is suitable for just one dependent variable at a time right? So should I do the same multiple regression analysis multiple times as I have multiple dependent variables? Second, my independent categorical variable has number 1, 2, 3 and 4 right now. Is this okay for the analyses? Thanks again -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/ ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD -- Jon K Peck[hidden email] ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

 In reply to this post by bdates Thanks! I will then dummy code the variable. However, how can I get any more insight in the specific linear relationships? Can I get something like multiple comparisons with multiple regression? -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

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## Re: test with multiple independent and dependent variables

 I want to know the effect of season (4 groups) and weather conditions (multiple continuous independent variables) on physical activity variables (continuous). For example, is there an effect of season on sedentary time, or is there an effect of season on standing time, is there an effect of sun hours on low intensity activity? I was first trying glm-->multivariate but it didn't work with the independent variables weather conditions, when I tried to add these to the independent variable season. Brian advised me to use multiple regression (analyze-->regression) so that's what I am trying now. Therefore I wanted to know if you can get something like multiple comparisons with multiple regression. Thank you -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

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## Re: test with multiple independent and dependent variables

 In reply to this post by spssdummy One reason that manova might "not work" is the lack of d.f. for the analysis. For multiple regression, you have several d.f. on the right hand side of the equation, only 1 d.f. on the left. For any analysis at all, you need at least as many cases as there are d.f., and it is better to have twice, five times, ten times, ... depending on the size of the underlying R2 you expect in the model.  Remember - for simple MR, the R2 achieved by /artifact/, by over-prediction, is (predictor d.f.)/cases.  The actual prediction has to be visible against that magnitude of "noise". In my few exercises with manova, I've figured the same rule of thumb for N seems okay, but this time, taking the "total d.f." as (d.f.-left side) times (d.f.-right side).  And that comes out too big for small data sets. With the problem that you eventually describe, it seems to me that if you want a /test/, you want to create composite scores - probably for both dep. and indep. vars.  That reduces the test to multiple regression, with fewer variables. If this "overall test" is good, then you are justified in exploring its components. If you are not choosing manova for its /test/ - Is there a proper rationale for using it at all?  Do you have this hypothesis, that you are looking for a useful, not-obvious contrast among the dependent variables?  Manova is notable for being hard to interpret.  The complications of figuring out "confounding", etc., among the independent vars in multiple regression are magnified by simultaneously trying to figure out what is happening among the dependent variables. (Not really bad for 2; "it depends" for 3; probably bad for 4 or more dep vars.  But may be okay if you totally know what you are doing.) -- Rich Ulrich From: SPSSX(r) Discussion <[hidden email]> on behalf of spssdummy <[hidden email]> Sent: Monday, June 10, 2019 11:21 AM To: [hidden email] Subject: test with multiple independent and dependent variables   Hey, For my research I have multiple independent and multiple dependent variables (and some covariates). One independent variable has four categories while the others are continuous. The dependent variables are all continuous. I think the covariates should be continuous but apart from continuous variables I also want to test for the effect of categorical variables like gender and employment status (how should I do this?) My guess was to try MANCOVA, so I did this with the independent variable and the 4 groups, and the dependent variables + covariates. It worked (except that I don't know if it is appropriate to put gender and employment status etc. under covariates). I then added the continuous independent variables to the test, but it didn't work (some warning that it was too much). - How can I deal with gender and employment status? - Should I use a different test for the analyses, or just for analysing the effect of the continuous independent variables on the dependent ones? Thank you!! -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/ ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

 In reply to this post by Bruce Weaver Thanks! There are indeed multiple questions but I do try to see it as one question per dependent variable so 5 in total in my case. If I have the dependent variable sedentary time, i want to examine which independent variables affect it so I add all the independent variables (season, weather conditions) in the multiple regression model and do this again for each dependent variable if I'm correct Then I do like to know in what way exactly for example season affects the dependent variable. I might find an effect but with dummy coding all groups are only compared to the reference while i want to compare all groups to each other, which I don't know how to achieve with multiple regression. -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

 If I understand the question/issue correctly, you just simply run a series of regressions where you alter which is the excluded reference category. The only meaningful thing that will change, however, is the p values since the rest is all algebraically equivalent. There's an option to use contrast coding, but I think that introduces a complexity that I don't think you need. Jeff -----Original Message----- From: SPSSX(r) Discussion <[hidden email]> On Behalf Of spssdummy Sent: Tuesday, June 11, 2019 7:49 PM To: [hidden email] Subject: Re: test with multiple independent and dependent variables Thanks! There are indeed multiple questions but I do try to see it as one question per dependent variable so 5 in total in my case. If I have the dependent variable sedentary time, i want to examine which independent variables affect it so I add all the independent variables (season, weather conditions) in the multiple regression model and do this again for each dependent variable if I'm correct Then I do like to know in what way exactly for example season affects the dependent variable. I might find an effect but with dummy coding all groups are only compared to the reference while i want to compare all groups to each other, which I don't know how to achieve with multiple regression. -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

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## Re: test with multiple independent and dependent variables

 In reply to this post by Jeff A Thank you! I still wanted to ask how to interpret the results for the dummy variables season. In my attached file summer is used as the reference and then there are the standardized beta coefficients but I am not sure if these are actually like a comparison to the other seasons (so the ones next to spring, autumn, winter).   -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

 In the sample, Autumn has the lowest predicted value on the DV followed by Winter, Spring, and then Summer. You have little evidence that there is a non-zero difference in the DV across any of the seasons in the population from which the sample is drawn. ...many might say that none of these differences reaches the traditional .05 level of statistical significance. You don't really need to do further comparisons if you're simply interested in null-hypothesis-statistical-tests, since if there is no meaningful population difference between the three included seasons and the summer reference where all three included seasons are less than summer in the sample, then they can't be meaningfully different from one another - E.g. if the Autumn/Summer p value = .146 and Autumn has the largest difference from Summer, then all other contrasts/comparisons will have p>.146. Trying to interpret standardized coefficients here doesn't seem very useful or meaningful to me. -----Original Message----- From: SPSSX(r) Discussion <[hidden email]> On Behalf Of spssdummy Sent: Tuesday, June 11, 2019 11:12 PM To: [hidden email] Subject: Re: test with multiple independent and dependent variables Thank you! I still wanted to ask how to interpret the results for the dummy variables season. In my attached file summer is used as the reference and then there are the standardized beta coefficients but I am not sure if these are actually like a comparison to the other seasons (so the ones next to spring, autumn, winter).   -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

 Thanks! Indeed for this dependent variable no further analyses will be needed. However, when looking at the descriptives, the values for the dependent variables seem to be different, with the highest value for winter, and then autumn, summer and spring are lower. So I don't know why the predicted results are so different. -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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## Re: test with multiple independent and dependent variables

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## Re: test with multiple independent and dependent variables

 I tried that but SPSS couldn't handle it for some reason. 5 dependent variables, 1 categorical independent (4 groups), 7 continuous independent variables, and multiple categorical and continuous covariates were entered. -- Sent from: http://spssx-discussion.1045642.n5.nabble.com/===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
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