model

  1. 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...
  2. 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...
  3. 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...
  4. 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...
  5. 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...
  6. 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()...
  7. 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...
  8. 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...
  9. 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...
  10. 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...
  11. 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...
  12. 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...
  13. T

    HELP - citation model in R

    Hello everyone. I need help with the citation model as explained in This article "Bibliometric tools applied to analytical articles: the example of gene transfer‐related research" The model is expressed as C=KY+S C=cumulative number of citation Y=article life K=citation rate (number of...
  14. A

    Drift Diffusion Model

    Hello I have RT-Accuracy data. I want to estimate the parameters of a drift diffusion model (Ratcliff, 1978). I am assuming that: v(t)=v(t-1) + v + e(0,s). meaning that at each giving time evidance is accumulated from a normal distribution with expected value v and noise s. I am very very new...
  15. N

    I am too new for words

    Ok, I am quite new to statistical analysis and will be training myself. I am working in Quality Assurance at a nuclear site. Here is the premise: Many models of issue deficiencies us a "Bird's Triangle" model. Industrial Safety for example. In each tier of blocks the numbers change to indicate...
  16. C

    Hierarchical regression for a complex model

    So I am testing my own model but it is more complex than I have dealt with before. I know I need hierarchical regression, and I'm using SPSS (I have no choice in programme, sorry), but I can't find a tutorial close enough to what I'm doing to be sure it's right. I have one IV (3 categories...
  17. S

    Defining model - are my samples too small?

    Hello, I am attempting a valuation of a non-market good. This non-market good is made up of a number of component parts. I have conducted a meta-analysis of these valuations and am attempting to model these to establish which explanatory variables given about the good explain values given...
  18. C

    Suitable Model

    Hi all, I wonder if anyone could help me, i'm looking for an idea or two :) I work in the financial sector and we are looking into ways of predicting the behaviour of customers following changes to rates on some of our products. The current process involves looking at previous rate...
  19. Y

    Help with research model

    I am in need of a quick statistical advice for a study I planned, and I hope you can help me a bit with it. I'd really appreciate your expertise. Here's a link to the model: https://drive.google.com/file/d/0B_S37tP6GGAAZWU2ZkxuZk9NVVVDaUNYVzZyWlBjVmZLRmdV/view?usp=sharing The model looks...
  20. W

    Comparing self made models

    Hello! I have a quenstion about comparing models. Not models fitted by R itself, but user defined models. Ill explain through this example: Dataset: Tree Diameter Biomass Model1biomass Model2biomass 1 10 50 45 60 2 7 35 52...