clustering

  1. C

    I want to split a column of data into stastically significant groups

    I want to split a column of data into stastically different groups I have a column of average annual temperature data. According to theory, whether the temperature is very cold or very hot (or moderate) it will have an effect on a species that I am interested in. So what I want to know, is if...
  2. T

    clustering similar lines (on chart)

    Firstly sorry if this is the wrong forum for this question. I have a matrix made up of distances in meters and for every distance I have an R2 value, the chart I plot in excel is a simple line chart that shows a bunch of lines that could 'seem' to be clustered and have a relationship as the...
  3. S

    Motivational and Behavioral Classes for User Segmentation

    Hi everyone, In the course of a research project with a sample size of > 1000, I intend to first group users in unique motivation/motive classes. These will be derived from qualitative user statements which are manually attributed to multiple binary motivation items- min 5 up to 10 items such...
  4. U

    Adjusted Chi-squared test for clustered binary / categorical data

    I'm looking for some assistance in statistical analysis with R (ideally), but also some general stats advice. This follows from a review which identified the need for me to adjust for clustering of relatives within family groups in my data set. I am investigating cardiac phenotypes (I'm a...
  5. L

    xtprobit regression with a cluster

    Hello everybody, I have a huge problem that I hope you can help me to solve, since I have not found anything helpful in the web. I have a WIDE dataset, made of: - a variabile called "people" (with 660names) - 32 variables, called "action1".."action32", with value = 1 or = 0 (in order to...
  6. P

    By which dimension to cluster standard errors in linear regression?

    Hello, This is my first post to this forum. All direct help, as well as references to other sources discussing the subject, are greatly appreciated. I am not sure by which variable/dimension to do clustering for standard errors in a specific linear regression model. I have firm-level...
  7. trinker

    clustering

    I read in my design book that propensity scores and clustering can be used as a means of matching observations in a quasi experimental design. So I decided to to give it a whirl in R (the clustering as I know he's going to go over propensity scores in depth). I read a bit about clustering but...
  8. A

    Partially linear (semi-parametric) difference in differences models with clustered SE

    Hi All, I'm digging through stats literature, and not really finding what I need. I'm looking for a difference in differences estimator that uses the within transformation (subtracting off the means of all variables to lose the fixed effects), that can accomodate more than one non-linearly...
  9. P

    Multi-level models: xtmixed vs. xtreg, re

    Hi all, I am dealing with a panel and multi-level data. Specifically, I have data (prices, etc...) related to numerous items (each identified by a unique id) within a product category in a given period. The measurements for the same item are repeated several times in this period: that is, for...
  10. S

    Stratifying data with chi square analyses

    Hi I've carried out a study where 26 participants had to make decisions about 20 scenarios (i.e. 520 decisions in total). Decisions are marked as 'correct' or 'incorrect' i.e. are binary. I believe that chi square analysis is the "go to" in these situations. I was wondering if there was a...
  11. A

    Advice on sample frame and sample size

    I'm involved in a 4-yearwater supply, sanitation & hygiene project for mainly pastoralist (nomadic)communities in northern Kenya. We need to conduct a baseline survey for anumber of indicators against which the project will be later measured. As anon-statistician I'm struggling with applying...
  12. R

    Variance, means and clusters

    I have a question for you, hopefully it's not too trivial, but I a'm not an expert :) I have the distribution, within a certain population, of a group (G) of variables (urban quality of life indicators, but that's not so relevant, I guess) that may or may not be correlated with each other...
  13. Y

    Cluster analysis in SPSS

    Hi, I have 2 questions about conducting a cluster analysis in SPSS. 25 animals were tested by being presented with 2 different stimuli. They make 3 types of calls but the number of each type of call differ by the type of stimuli presented. For instance, for call1, call2 and call3...
  14. W

    Clustering Analysis when to stop the algorithm?

    I have a data set, let's assume 1,000 points, that I am attempting to form into clusters. I am using Hierarchical clustering in the sense that I start with 1000 clusters then for each point I join it together with the next closest point until i have cycled through all 1,000 points. Now I have...