data analysis

  1. D

    Question about model validation.

    I'm working on a problem on my own (not for class or work) and I just wanted to get some outside opinions before I progress further. As far as my background, I've taken some introductory statistics courses for psychology majors, and an intro probability and statistics course for engineers...
  2. R

    SPSS Question Regarding entering data and calculation

    Hi, i am doing a research on stress level and i have 2 questionnaire and the total no. of respondents is 60. First questionnaire has been measured on a 6 point likert scale and it has total 16 questions. Second questionnaire has been measured on 5 point likert scale and it has total 46...
  3. H

    Re: Help needed for forecasting model

    Hi, I have a dataset of some monthly usage values. I have to forecast the for the next 12 months. I have taken log of data for ease of use. It seems to me that ARMA(2,0,2) model fits best for it. Can you confirm if I am right or wrong? If it is, please tell me which one fits the best. Also...
  4. A

    What analysis should I run?

    Hi, I am not sure which analysis to run based on what I am trying to figure out, any guidance is appreciated. The research question is- are certain ethnicities more likely to report their ethnicity in the online classroom? Data- I have a variable of ethnicities (1= Caucasian, 2= African...
  5. W

    Minitab/Excel to Analyze Data - What do I use?

    Hi, I've been collecting data from a couple different experiments I've been running the lab. I run a mixing system through runs with solid material. The material is the same but some of the properties keep changing when I put it in (pH, %-solids) and are recorded through tests. I take T=0...
  6. K

    crazy p-value

    I am taking data analysis, and am having a bit of trouble. It has been a couple years since i took intro to stats, so i am very rusty. I performed a t-test (two sided, and both alternates) on Sleuth 2 ex0222, and I get a p value with an negative exponent. this seems ridiculous to me, and I...
  7. C

    Whether / how to combine 2 linear equations for different variables, and weighting

    I'm analysing results from measurements of 2 variables (a, b). The goal is to use them singly or together to determine a 3rd variable, c. All 3 variables are instrumented, measured data (not social science). We made over 5000 simultaneous measurements of a & b. Our equipment software gave us...
  8. W

    Finding specific terms in several files.

    I have several documents, and would like to see which files contain a given term. How to do that in R?
  9. A

    Help With The Preffered Package Type Assessment

    Hello there to everyone! I have the question concerning the underlying data analysis methodology. Here is the small introduction. There is a data from the e-commerce site about its customers' purchases and there are 875 observations total. Each observation consists of 5 values. Scales of value...
  10. T

    [RapidMiner] Decision Tree Parameters in RapidMiner

    Hello I was wondering if somebody would kindly explain to me the different parameters I can use on a standard decision tree. By parameters I mean the following: Criterion, minimal size for split, minimal leaf size, minimal gain, maximal depth, confidence. How would I determine what those...
  11. M

    Finding a value to show there's significant differnece between two population means

    I'm working with two data sets and want to compare the difference of means between two particular rankings between two different years. My boss wants me to find a number to prove there is significant difference between these means. I am wondering if there is a statistics equation to find this...
  12. M

    We have found statistical differences with t-tests, but there must be more!

    Hello TS users, The attached data set refers to patients that had an operation, a vast number of measurements were taken before and after. We have found some evidence of improvement in questionaires for pain scale (VAS), ability of living (RMS & ODS) and walking distance, all tested using...
  13. Z

    Survey Analysis

    Hey Guy's I really need your help. I am not a statistician. I have to analyze surveys that have 6 observations (people) and 20 factors (food preference with answers; like, dislike, neither or no) What method should i use to analyses this on SAS or Excel
  14. N

    Matched vs. Unmatched t-tests

    I am conducting a t-test and have to choose between an unmatched and matched test. I am looking at the vaccination percentage rate between men and women in a given year. Would this be a matched test? My understanding is that in a matched test, the two variables need to be independent, but I am...
  15. C

    Regularized Canonical Correlation Analysis

    Hi, I have a question about sample size and regularized canonical correlation analysis. Is a sample size of 15 unreasonable to use in a regularized canonical correlation analysis? If one has lots and lots of potential explanatory variables (multicollinearity expected) and multiple response...
  16. C

    Canonical Correlation (Package CCA)

    Hi there, I'm using R (and package CCA) trying to perform a regularized canonical correlation analysis (There are 12-13 "response" variables in one dataset, another dataset of a whole lot (i.e. >400) of potential "explanatory" variables, but only a sample size of 15). Gonzalez et al. (2008...
  17. A

    Joint and Marginal Densities.

    I am having some problems grasping the concept of these joint and marginal densities. It would really help if someone could provide me with an answer for the following question: Find the joint and marginal densities corresponding to the cdf F(X, Y) = (1 - е^αx){1-e^βy), x > 0, y>0, α >...