statistical analysis

  1. R

    How to create an unbiased fit to the data (Keyboard log data for each user)

    Hi all , So I have a very simple distribution of events (eg user keyboard log for five employees). Now if suppose I consider frequency of each key pressed for a single user, and for all users. And then suppose I want to see what distribution this data follows ( without any bias toward any...
  2. M

    Which test to use

    Hi all I am a language teacher, and, like many of them, I am unaware of the test I should you for statistical analysis of the data available with me. In fact, I want to see which of the skills my students are good at, and which one they are poor in. I have data for five skills, i.e. Writing...
  3. L

    Hierarchical Regression Analysis - is this the correct technique

    I am proposing a study to find out whether cognitive restraint, disinhibition and hunger predict weight gain in pregnancy. However, I know from previous research that this effect differs depending on BMI category. Am I correct in saying I could use a hierarchical regression analysis, where...
  4. A

    How to analyze survey data with three levels of data in SAS?

    We analyze data from a European survey (34 countries ) for quality of life , the sampling procedure is described as a " multi-stage stratified and clustured sampling design " . Our outcome variable is binary. There are three levels of data to be taken into account (individuals, regions...
  5. N

    Tomographic map of 3D data with a dimension described by probability distribution

    I have a three dimensional data set. Two first components are the exact values of(X,Y) and for the third dimension I have a probability attached to each point for each given value of z between (0,1.5). for example P(x0,y0,z0)=0.24 and the probability is not necessarily Gaussian, it can be...
  6. L

    statistical Analaysis? NEED HELP... URGENT!!!

    I am working using secondary data that was originally collected for another purpose. The data is from a teen pregnancy program among Latino youth. The program had a control group and an intervention group and collected baseline and follow up data from both control and intervention. the...
  7. L

    Investigation outliers, could data mining be a solution?

    Hi everyone, This is my first post. :wave: I am currently working on a project to investigate the reason for why these providers are outliers on the dataset on a whole. I am finding it very tricky to find statistical methods that "investigate" outliers- as in show you why they are outliers...
  8. F

    something like a paried t-test for dependent variables

    Hey, can anyone recommend a test for the following problems. 1) Say I have repeated measurements x_1,...,x_n and y_1,...,y_n such that each measurement may depend on the past. How can I test whether the means in both tests are equal, i.e. mean of x_1,...,x_n equal to mean of y_1,...,y_n ? I...
  9. C

    urgent stats help

    I need some help desperately. I would like to find out whether there is any difference between three conditions using a t test (I dont know if I need an independent or paired t test), and have tried this in SPSS but cannot seem to make sense of it. Basically I have 6 participants who watched...
  10. V

    Statistical Analysis: Which measure of association for me?

    My research hypothesis claims that there is a relationship between my independent variable, student’s economic status and the dependent variable, SOL test scores. the null hypothesis states that there is no relationship between the two variables. This is quantitative, and it is discrete. This...
  11. C

    Statistical analysis on online betting industry?

    Hi! i'm currently working for an online betting company and i would need some help on how to come up with risk indications. I believe some statistical tools may help me assess the gravity of risk of a certain event or user. For example: 1. a certain player bets on an average of 100 per bet...
  12. T

    How to statistically analyse this experiment? Also confused about IVs/DVs, pls help!

    Hi, I'm doing a hypothetical test, so if it doesn't make theoretical sense, just ignore please! :D The study is longitudinal one lasting a year in which memory skills of children are assessed with a test quarterly. So at the start, 4 months, 8 months and at the end. The study is...
  13. D

    Chi Square, Likert Scale, and Within Group - reasoning

    I am hoping some really smart folks can answer this question for me and provide some sage and learned advice to help me finish the last piece of my PhD dissertation research. Background: I have completed a data study, using a Likert Scale (1-5), on importance of an element within an...
  14. O

    Statistical analysis of Profits - use of U-test

    Hi We have been working on a project where we have 2 or more trading agents on a market stock and for the outcome we have the profits that each trader generated after running 1000 times or more each market session. We need to statistically compare the profits of this traders to know which one...
  15. S

    Trouble with Wilcoxon signed rank test - please help

    Firstly...I'm an absolute stats novice. I am assessing the urinary toxicity of a procedure by comparing baseline and 6 week International Prostate Symptom Scores (IPSS) for 10 patients. I am applying the wilcoxon signed rank test - however through all my "googling" there appears to be 2...
  16. A

    How to prove a non negative definite matrix has to be a variance-covariance matrix?

    I know this is a iff condition,and the reverse is easy to prove.But I am having some difficulty to prove that all non negative definite matrices are variance covariance matrix.From what i have collected from wikipedia,I tried to prove it this way. Let A be a non negative definite matrix...
  17. A

    What is the role of relational databases in research design and hypothesis testing?

    I am taking a database management course with a focus on relational databases as part of the requirements of a degree program. One of the course requirements is to apply relational database techniques to a case study. In other words, students have been asked to identify a hypothesis and research...
  18. E

    Statistical Analysis Plan - help!

    I'm doing a summer research project on trends of anxiety and depression. Unfortunately, my preceptor has disappeared in the meantime and I'm left to fend for myself. I've done an extensive literature review, and now have to develop a Statistical Analysis Plan (SAP). While I understand that there...
  19. M

    Regression Hypothesis

    I am not good at statistics that is why I am seeking help in this forum. Thanks for any help in advance. My research hypothesis is Student will score high on optimism, this optimism will be highly correlated with more positive attitude towards fat children, and it will further enhance their...
  20. W

    What does uncorrelatedness and independence imply?

    Dear all, I'm currently reading papers of statistical modelling. I encountered with the concepts of uncorrelatedness and independence. I understand the definitioins, but I am wondering what are the real effects they can make in statistical analysis? For example, I have a dataset and I use...