model

  1. 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?
  2. O

    SPSS-PROCESS-HAYES Mediation-Model 84

    While HAYES offers guidelines on how select his basic models in SPSS (http://www.regorz-statistik.de/en/tutorials_en.html), I am trying to write the syntax for his Model 84 (picture below) I have 956 respondents, and my X (indep. var) has 4 cases. My solution: process...
  3. P

    Calculating model (Analytically)

    Hi, can anyone help me out with this question? Assume that the true data generating process (the true model) is: y = 20 −30(x + r) + 4w + ê. Suppose that we also know that E(ê|x) = E(ê|w) = E(ê|r) = 0, Cov(x, w) = 20, Cov(x, r) = Cov(w, r) = 0, Var(x) = 10, Var(w) = 8 and Var(r) = 6. What...
  4. B

    Model suggestion

    What is the best model to study in-person attitude change over time?
  5. Y

    Which model/statistical test should I use?

    Hi, Soon I will be performing an experiment where I must grow 4 different plant species under 4 different stressors, each stressor containing 4 levels of 'severity' of the stressor or in other words a difference in concentration. Growth of the plants will be measured over 22 time points, but...
  6. L

    model for an exponential function

    I am struggling with an exponential kind of function (it's stock market so not a function itself). It's the function of bitcoin basically. As you can see it's exponential-like increasing since 2011. Now I don't give this example for price prediction but for genuine interest...
  7. S

    Stata project JOB CASH WORK

    Hi, I am new on this forum and completely new to stata. PROJECT FOR MONEY Nevertheless, I am supposed to prepare a small project about alcohol consumption (in a couple countries - any) based on a couple variables like sex, type of alcohol, country, tax, GDP, etc. The project should consist of...
  8. D

    HELP WITH DATASETS COMPARISON

    Hello everyone, I am a stats-beginner and I need help to understand if it is possible to compare two datasets. I am currently looking at the Residential Energy Consumption Surveys (RECS) databases, specifically to the 2015 and 2009 surveys. There have been some major changes in the 2015 survey...
  9. J

    drawing up a mediation model with 2 predictors and 1 mediator

    Hello all, I was hoping someone could help my understand where a certain value comes from in my data output (using SPSS). I have performed a hierarchical multiple linear regression and the used PROCESS to find that my model has 2 predictor variables which both go through the 1 mediator variable...
  10. S

    Constant not sig. in multiple regression - does it matter?

    I did a hierarchical multiple linear regression in SPSS with three predictor variables. All the variables have high F-values and are highly significant at each step of the model, but the constant is not significant (0.079) in the last step. Should I disregard all the results just because of...
  11. L

    Which model/test should I choose? (GLM..?)

    Hello! I'm new to statistics but I am getting really stuck with my data so I hope someone could help me to choose the best statistical test. I have some test (dummy) data. I have data from 64 different hospitals, for 5 different countries countries, over 5 different years. In all of the...
  12. P

    Whats is the method to analyze characteristics from two groups?

    Hello there, Im new in the statistics world and i hope that you can help me. i have two groups of sample that are divided by one y (depended) variable y = binary, is a good employee or no then i have ten variables (x) divided into demografic variables and profile test. Example: age, emotion...
  13. L

    The bootstrap method for medical modelling

    I am part of a team creating a model for paediatric hospitalised patients and would appreciate some help. We are looking to produce an accurate model for weight estimation, using input variables of gender, age and mid-upper arm circumference. This would be helpful as some children arrive in...
  14. M

    Which is the better prediction model?

    The aim is to predict the breakdown time of a machine as a percentage of scheduled hours for the next day. So my time series looks like this, Break_down_percentage = 7%, 8%, 10%, 6%, 12 % etc. There are 315 data points which can be used to test the different models. I used ets(), arima()...
  15. D

    Evaluation of the most suitable model between LASSO and Forward stepwise selection.

    Hello, please take into account this: I'm a beginner :) I need to assess which of the two following specifications of a model is more suitable and explain it. This is what I obtained running properly on R the tools I had: FORWARD STEPWISE SELECTION: LASSO REGRESSION: This shows the...
  16. D

    How do I assess which is the most suitable model?

    Hey everyone, I am making an R project, and I have computed the models using all the methods we've studied in the lectures (particularly Lasso and Forward stepwise selection). In the conclusion, I have to assess which is the most suitable specification model. Could you help me writing...
  17. C

    Repeated Measures model with Covariates

    Hi Everyone, i am struggling with finding a good way to analyze a dataset. The design is this: I have 25(n) subjects, all of them are tested in an experiment under 9 conditions. I estimate an electrophysiological index (idx) in every condition for each subject. Now I want to ask whether the...
  18. I

    Multivariate models - standard error help

    I have 2 multivariate models created in R concerning nutrition Model 1 = -11.5±1.68 + 0.56±0.562 Intake + 16.6±0.165 Potassium concentration Model 2 = 16.6±0.123 Potassium concentration Both of these have come from the same data set. My question is, is it right that the standard error...
  19. G

    Cave Temperature Analysis, Real life management issues.

    Hi, I've taken math course's up to Calc III and Diff Eq, but never a statistics course. So I was hoping this forum could help me. I am working with 10+years of temperature data taken from several loggers throughout a cave system. The loggers record temperature every 30mins, which I have...
  20. B

    Model conception

    Hello! I have a basic stats question: I want to model a phenomenon, and estimate parameters. How many observations would I need, to be as accurate as possible? I think it might have something to do with the degrees of freedom, but I am not exactly sure how to use this information. From the...