Recent content by a_zensun

  1. A

    test of significance for comparing change between two groups

    What test for significance is best to use to test the difference between the change of a categorical variable in a control group and the change in a pilot group? I do not think I can simply compare the 'after' for each because the 'before' for the two groups was statistically different - they...
  2. A

    multiple-response frequencies

    Should frequency tables for multiple response questions be calculated based on total number of respondents or total number of responses?
  3. A

    when to weight frequencies and variables, and how to determine category boundaries

    Should income categories of a sample intercept survey be weighted to match the income proportions of the population of a city? Also, what guidelines should be used when deciding on category breaks between income groups? When looking at responses to various questions between income groups...
  4. A

    Rao-Scott chi-square correction

    I have a multiple-response variable, and believe I need to use a Rao-Scott correction to the chi-square test. I am using Excel and only have the tools/information to do a first-order correction. I want to make sure I am doing it correctly... chi-squared (corrected) =...
  5. A

    multiple-response categorical variables - what is "n", chi-squared

    Hello, I am doing independence checks (chi-squared tests) on two variables. One of the variables is of the interval nature and the other is a multiple-response categorical variable. Couple of questions: 1. What is "n"? The number of respondents, or the number of responses, or...
  6. A

    Test for correlation and differences in correlation - nominal and interval variables

    Hi, I've got two types of variables - nominal (mode choice (e.g. car, bike, etc...) and interval (income range (e.g. 10,000-15,000, 15,001-20,000, etc...). I am trying to figure out the best test to see if the variables are correlated, and then I want to test to see if the correlation is...
  7. A

    Hypothesis testing - ttest difference in 1-tail versus 2-tail

    Hi, I am runnings some Ttests, and when I conduct a one-tailed test to see if Variable "a" is greater than Variable "b" the result says to reject the null hypothesis, but when I conduct a two-tailed test to see if Variable "a" is different than variable "b" the result says not to reject the...
  8. A

    measuring error rates

    Hello - I've got a very basic question, but hoping for some help. Not even sure if this statistics or just algebra. I am trying to determine the error rate for a parking occupancy survey. Surveyors walked many blocks at different hours of the day and counted cars parked at legally available...