1. U

    Help determining start values of coefficients for a nonlinear model

    Hi everyone. For a dataset consisting of three quantitative variables, H, M and W I have to build a non linear model of this form: E(H)=b0+b1*M+(W/(b3+b4*M)). I tried using the "nls()" function in R, but I don't know how to determine the start values of the coefficients, b0, b1, b3 and b4. Can...
  2. M

    Spurious Regression with non stationary time-series

    Hi everyone, I'd like to have a confirmation on the correctness of the following interpretation: Let say that we want to run a very simple regression like the following one: We are regressing two I(1) series since x and y are assumed to be both described by a random walk process. The errors of...
  3. U

    Doubt on a model

    Hi everyone, for an universitary assignment, I have to model one dependent variable H based on two other independent variables, M and W; the model I have to fit to the data is this: E(H)=b0+b1*M+(W/(b3+b4*M)) do you have any clue on what kind of model this is and how can it be adapted in R?
  4. S

    Multiple Regression

    I have been given a college assignment and need to interpret these results (see attached). From what I can understand, the Annual Personal Outcome is the DV and there are several IVs (i.e gender, sexual orientation etc.). As such, has a multiple linear regression been conducted here? I'm...
  5. K

    Difference between simulating the dependent variable and simulating the error terms and adding them to the fitted values values assuming normality?

    What's the statistical difference between simulating the dependent variable and simulating the error terms and adding them to the fitted values values assuming normality (gaussian GLM)? Say I'm doing a simple multiple regression on the following data (R): n <- 40 x1 <- rnorm(n, mean=3, sd=1)...
  6. S

    Treatment of Coefficients from Regression Using Lagged Independent Variables

    I'm running a regression on two time series of financial returns, one dependent and one explanatory/independent. For the explanatory time series, I'm creating several lagged versions and using all of them as independent variables in in a multiple linear regression. My question is, how do I...
  7. L

    What statistical test should I use?

    Hi there, I'm currently in the process of carrying out a systematic review and I've gathered cost estimates from studies for a specific type of treatment (with two different approaches), I am interested in finding out if these costs have decreased over time. I have 40 cost estimates for the...
  8. E

    Ordinal Logistic Regression

    Hello! I am trying to perform an ordinal logistic regression (or at least I think I am) and I'm a bit stuck. My variables are all categorical or ordinal: DV: High, Medium, Low IV: Parent Gender: 0,1 Child Gender: 0,1 Essentially, I am trying to understand if a parent's gender...
  9. S

    How to Improve my Hosmer-Lemeshow Goodness of Fit Significance Value

    Hi, I'm just wondering if anyone here can help me. I'm making a model for my logistic regression. For the variables, I'm using 1 Dichotomous Dependent Variable (Financial Distresss, Y) and 2 Continuous Independent Variable (Corporate Governance Score, X and VAIC Score, Z). I'm using logistic...
  10. F

    Two dummy variables are mutually exclusive

    Hello all, I have a problem for a university assignment that two dummy variables are mutually exclusive. The task is to estimate what can increase certain diseases in dogs using regression. In the sample there are several factors (Lives in city yes/no, age, male/female etc....). Then there is a...
  11. T

    How is conditional main effect interpreted when there is interaction?

    I have a question about multiple regression. May I kindly ask how should I interpret the conditional main effect when the interaction is 0 and the coefficients have opposite signs, more specifically if one of the interaction term contains zero such as angle or time. Please see an example...
  12. victorxstc

    SPSS - Using mixed univariate ANOVA (UNIANOVA) or mixed linear regression (MIXED) instead of repeated-measures ANOVA

    Which process is better for using instead of Repeated-Measures ANOVA (SPSS syntax: GLM -- GUI command: Analyze --> General Linear Model --> Repeated Measures)? and Why? (1) Mixed univariate ANOVA (SPSS syntax: "`UNIANOVA`" -- GUI command: Analyze --> General Linear Model --> Univariate) (2)...
  13. H

    Statistical tests - help please!

    Hi all, I am writing a project plan and I am struggling with the statistical analysis plan as I am in the early stages of learning. I was hoping someone could guide me with what stats tests I could conduct with the following primary endpoint - thank you. Alternative hypothesis: treatment is...
  14. V

    Logistic Regression interpretation

  15. R

    Help deciding which spss functions to use

    I'll start off saying that stats in general has never been a strong point for me :D The variables i am using are; Gender Age Relationship Status Number of dependants Profession Neuroticism (Higher score = higher neuroticism) Affectivity (Higher score = positive; lower...
  16. T

    Uncertainty about normality (Q-Q Plot)

    Hey everyone, I've done several linear regression. Now I would like to test if my residuals are normally distributed. That is how my Q-Q Plots look like: But I'm not sure what to make of the Q-Q Plots. Most of them are pretty much on the line, except for the beginning and ending. What do you think?
  17. N

    Multivariate logistic regression?

    Hi! With my master thesis project, I only use categorical data. I have one independent variabele, with four categories. My dependent variables are dichotomous (yes/no). I would like to use logistic regression to calculate the odds that when the categories of my independent variable are...
  18. S

    Getting ANCOVA results with a regression

    Hello ! My outcome variable is a change variable that can take positive and negative values. My ancova has 1 factor (with 3 categories) + 1 continous covariate + a categorical noise variable. Only my outcome variable has missing data. I have to do a sensibility analysis comparing results from...
  19. L

    How to study the effects of alcohol consumption on happiness & cognitive function?

    Hello, I want to study if there's a relationship between alcohol consumption and happiness + cognitive function. Most of my data is nominal or ordinal. To measure alcohol consumption: How often respondent has had an alcoholic drink during the last 12 months To measure happiness: Overall...
  20. M

    Logistic regression model - numeric predictors modification

    I am running a regression using multiple variables in order to predict a binomial outcome. Two of my variables are numeric, most are categoric. My two numeric variables are age and bmi. I have calculated an odds ratio for each of those variables (e.g. if the bmi increases with 1 point...