1. C

    Standardize one predictor variable or all predictor variables to solve multi-collinearity

    I was using a fixed-effects panel model with interaction effects when I realized that the VIF values are too high for some variables. I was advised to standardize the predictor variables to mitigate multi-collinearity. My question is that can I standardize just 1 predictor variable or must I...
  2. L

    Standardization of a variable

    Hello, before making a linear regression, how can I know if I have to standardize a variable?
  3. H

    How to standardize 3 data sets in SPSS

    Hello, I'm trying to standardize 3 data sets in SPSS to increase the power of my sample to 120 subjects in total. The 3 data sets were all conducted using the same procedure but at different times and the number varies between each of the data sets (Set 1: 50 subjects, Set 2: 34 subjects, Set...
  4. B

    Standardizing monthly sales figures in excel

    Hi everyone, this is my first post. In excel, I have approximately 723 rows of sales figures, broken down by month. I have an average monthly purchase (in Dec. 2014) of $24,500.47 and standard deviation of $76,232.24. The problem is, many of the rows have a $0 purchase (that member didnt...
  5. R

    Use z-scores in Repeated Measures ANCOVA?

    Hi everyone, My dissertation has participants answer three questions at four different timepoints in a video. For each timepoint, I have averaged the three questions for an average response per timepoint (4 scores). I also have a dichotomous between subjects variable, and two continuous...
  6. B

    Totally confused! re-scaling using rank ties command?

    Hi, Thank you all for all those kind helps all the time. I'm always getting useful advices here. This time, I have a question on making a composite variable and rescaling... let's say I have these three variables - V_club : number of clubs a respondent join (range 0 ~ 10) - V_talk ...
  7. P

    Demographics adjustment for combined counts

    Hello! My unit of observation was cities within a county. Since asthma counts were too small for each city, I decided to combine counts from various cities by a binary variable (all 'yes' cities combined and 'no' cities combined). How can I then adjust for demographic variables, such as age...