+ Reply to Thread
Page 2 of 2 FirstFirst 1 2
Results 16 to 25 of 25

Thread: What is the difference between an interaction effect and a moderator in regression?

  1. #16
    Omega Contributor
    Points: 38,374, Level: 100
    Level completed: 0%, Points required for next Level: 0
    hlsmith's Avatar
    Location
    Not Ames, IA
    Posts
    6,998
    Thanks
    398
    Thanked 1,186 Times in 1,147 Posts

    Re: What is the difference between an interaction effect and a moderator in regressio




    Perhaps you need to find some examples with data, and see if these things hold. If you had a continuousXcontinuous interaction, you could always bin one of the variables into groups and play around with some of these concepts.
    Stop cowardice, ban guns!

  2. #17
    Fortran must die
    Points: 58,790, Level: 100
    Level completed: 0%, Points required for next Level: 0
    noetsi's Avatar
    Posts
    6,532
    Thanks
    692
    Thanked 915 Times in 874 Posts

    Re: What is the difference between an interaction effect and a moderator in regressio

    Converting a continuous variable into a categorical one is bad bad bad bad bad bad

    Or so I was told in my program. I am still not sure how SAS handles interaction diagnostics or simple effect with two interval variables. Perhaps there is no reasonable way.
    "Very few theories have been abandoned because they were found to be invalid on the basis of empirical evidence...." Spanos, 1995

  3. #18
    Omega Contributor
    Points: 38,374, Level: 100
    Level completed: 0%, Points required for next Level: 0
    hlsmith's Avatar
    Location
    Not Ames, IA
    Posts
    6,998
    Thanks
    398
    Thanked 1,186 Times in 1,147 Posts

    Re: What is the difference between an interaction effect and a moderator in regressio

    It is not bad bad bad,..., when you are just playing around with concepts for fun. I get the loss of information, but you are more likely to find a practice dataset with two continuous variables than interval variables.
    Stop cowardice, ban guns!

  4. #19
    Fortran must die
    Points: 58,790, Level: 100
    Level completed: 0%, Points required for next Level: 0
    noetsi's Avatar
    Posts
    6,532
    Thanks
    692
    Thanked 915 Times in 874 Posts

    Re: What is the difference between an interaction effect and a moderator in regressio

    but you are more likely to find a practice dataset with two continuous variables than interval variables.
    I don't think it is possible to find a practice data set with two continuous variables that are not interval

    I think you meant categorical rather than continuous.
    "Very few theories have been abandoned because they were found to be invalid on the basis of empirical evidence...." Spanos, 1995

  5. #20
    Devorador de queso
    Points: 95,866, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Awards:
    Posting AwardCommunity AwardDiscussion EnderFrequent Poster
    Dason's Avatar
    Location
    Tampa, FL
    Posts
    12,936
    Thanks
    307
    Thanked 2,630 Times in 2,246 Posts

    Re: What is the difference between an interaction effect and a moderator in regressio

    Or there are differences in data across fields. For example I rarely come across interval data.
    I don't have emotions and sometimes that makes me very sad.

  6. #21
    Fortran must die
    Points: 58,790, Level: 100
    Level completed: 0%, Points required for next Level: 0
    noetsi's Avatar
    Posts
    6,532
    Thanks
    692
    Thanked 915 Times in 874 Posts

    Re: What is the difference between an interaction effect and a moderator in regressio

    That's amazing to me. I commonly work with money which is entirely interval.
    "Very few theories have been abandoned because they were found to be invalid on the basis of empirical evidence...." Spanos, 1995

  7. #22
    Devorador de queso
    Points: 95,866, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Awards:
    Posting AwardCommunity AwardDiscussion EnderFrequent Poster
    Dason's Avatar
    Location
    Tampa, FL
    Posts
    12,936
    Thanks
    307
    Thanked 2,630 Times in 2,246 Posts

    Re: What is the difference between an interaction effect and a moderator in regressio

    Oh my bad. I rarely use these "types" for classifying data (to me continuous, discrete, and categorical tend to be "good enough"). For some reason I read that as "ordinal" instead of "interval".
    I don't have emotions and sometimes that makes me very sad.

  8. #23
    Fortran must die
    Points: 58,790, Level: 100
    Level completed: 0%, Points required for next Level: 0
    noetsi's Avatar
    Posts
    6,532
    Thanks
    692
    Thanked 915 Times in 874 Posts

    Re: What is the difference between an interaction effect and a moderator in regressio

    Is discrete data count data? When data is a count, in practice, is rarely obvious to me. For example I never run Poisson regression with our data although arguably some of our results are counts [like how many times you receive services].

    I think of data usually as interval, ordinal, and nominal the last two being important distinctions when I run logistic regression. We have lots of ordinal data when we administer likert type survey data [although commonly we treat that as interval....]
    "Very few theories have been abandoned because they were found to be invalid on the basis of empirical evidence...." Spanos, 1995

  9. #24
    Points: 657, Level: 13
    Level completed: 14%, Points required for next Level: 43

    Posts
    57
    Thanks
    1
    Thanked 9 Times in 8 Posts

    Re: What is the difference between an interaction effect and a moderator in regressio

    Discrete data doesn't necessarily have to be count data. Gender is also discrete, i.e. you can only be male or female (ignoring politically correct arguments here..).

  10. #25
    Omega Contributor
    Points: 38,374, Level: 100
    Level completed: 0%, Points required for next Level: 0
    hlsmith's Avatar
    Location
    Not Ames, IA
    Posts
    6,998
    Thanks
    398
    Thanked 1,186 Times in 1,147 Posts

    Re: What is the difference between an interaction effect and a moderator in regressio


    Back to original topic:


    On the Distinction Between Interaction and


    Effect Modification




    Tyler J. VanderWeele
    Epidemiology Volume 20, Number 6, November 2009, pg 863.


    Feel free to read the whole thing and report back


    Stop cowardice, ban guns!

+ Reply to Thread
Page 2 of 2 FirstFirst 1 2

           




Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts






Advertise on Talk Stats