chi square test

  1. M

    Can I use chi-square for one nominal and one ordinal variable?

    Can I use chi-square test of independence if one variable is nominal and the other is ordinal, or do both have to be nominal?
  2. P

    Chi Square test

    Hi Guys, Hope you all are doing well. I am very new to statistics and I have a little doubt regarding what test to use to analyze my data. I have some bacterial population counts (4 bacterial species) for 4 different geographical sites. I wish to see the association between bacterial prevalence...
  3. P

    Calculating ensemble value for data with non-gaussian errors

    I have 10 data points each of which have non-symmetric (i.e., non-Gaussian) errors. That is, if 'a' is the central value (representing the median), then a^{+b}_{-c} means that 'b' is the positive 1-sigma error and 'c' is the negative 1-sigma error. I want to be able to get a representative value...
  4. H

    comparing two sets of data

    hi, i want to check whether the two samples can be drawn from the same distribution. can i do it with chi-square test? what are the assumptions i need for it? if i can't use chi square test - what can i do? notes about the data sets: - discrete - mostly increasing (in particular - not...
  5. S

    Randomness testing using frequency within a block method, chi-square statistic doubt.

    The chi-squared statistic under the frequency within a block method is defined as 4M summation of (proportion of 1s in block - 0.5 ) ^2 where M is the length Of each block I understand that this follows a chi-square goodness of fit test observed-expected frequency square. But where does this 4M...
  6. P

    How to apply Chi Squared test according to this Simulation?

    Hi there, I have been wondering about some points of Chi squared test. I would like to introduce the following scenario to better clarify my question: Let's say that one day while doing research on the city of Villy God has appeared to me and told me that city there are 10,000 adults...
  7. P

    Interpretation of the Likelihood Ratio Chi-Square Test Statistic

    Do I still use the Chi-Square distribution table to determine the significance of the Ratio Likelihood Chi-Square test statistic? I know you use it for the Pearson's Chi-square test statistic, so I am unsure whether to same rules apply. I calculated the Likelihood Ratio Chi-Square in SPSS...
  8. G

    What do I do when the chi-square assumption is violated

    Hello, I am looking at data to see if there is a correlation between an Independent nominal variable (3 level) and a hypothesized dependent nominal variable (2 levels). SPSS shows a statistically significant chi square and Cramer's V, but an assumption is violated. The expected count is less...
  9. D

    Help!

    I have a problem that is probably fairly simple but I have writers block. This is to do with unnamed animals. I have three tests I have conducted on different samples of animals. The possible outputs are simply alive/dead (please ignore the obvious moral implications). The tests are: Small...
  10. R

    Pearsons Correlation, Two-way ANOVA, Linear Regression Test, Chi-Square Test or None

    During research, you have asked your participants whether or not they have ever experienced financial difficulties (yes or no). You have three age-groups (16-20; 21-25; 26-30), and you predict that those in the 26-30 group have a greater risk of experiencing financial difficulties than those who...
  11. E

    Comparing groups/sites---need advice identifying variables and appropriate tests

    Hi, thank you for reading this and your potential input. This is a research study. I examined the prevalence of parasites in one insect species in an island ecosytem. Insects were collected from: Island 1: 3 sites (all very different elevations) Island 2: 2 sites (similar elevation)...
  12. Q

    Hypothesis Testing Help

    Hello fellow statisticians! it's been awhile since I've done stats and everything has completely escaped me. I'm trying to conduct hypothesis testing for the question below. Everyone has been using the Chi-squared test and I feel that they are wrong. I think it should be a poisson distribution...
  13. C

    Chi-Squared Help

    I am working on a homework set and I am very confused on this question...Can someone help me understand? What's wrong with this statement? Chi-square analysis will tell us whether two qualitative variables are correlated. 1.There is no statistical test for the correlation between two...
  14. R

    Degrees of freedom for Chi2 normality test

    I have found mixed information in regard to the number of degrees of freedom used to evaluate the chi2 statistics derived to check the normality of a given data set. In one case I found that df = Nbins - 3 and in other cases I have found df = Nbins-1 The idea of this test is to divide the...
  15. M

    Chi Square Test, Pre Post Study, Dichotomous Variables, Different Group Sizes

    Hi Everybody, I am a medical student. I am doing a Final Year Project (FYP) and need a little help. I must admit to being a novice statistican and apologise if this question is a little dumb. My FYP is a pre-post study (i.e. pre-intervention and post-intervention). Variables in my study...
  16. K

    [SPSS] Comparison to homogeneous distribution.

    Hello. This is my first post here, please forgive any mistakes. I am designing the statistics for a project. The aim is to compare samples taken against a perfectly homogeneous population. I have identified both Similarity Factor and Chi-squared as potentially good statistics to utilise. I...
  17. 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...
  18. C

    chi-squared hypothesis test of homogeneity using R

    A survey of drivers was taken to see if they had been in an accident during the previous year, and if so was it a minor or major accident. The results are tabulated by age group: \begin{array}{c|lcr} \text{Age} & \text{None} & \text{Minor} & \text{Major} \\ \hline \text{under} 18 &67 &...
  19. J

    Pre/Post Comparison of Percentages, Two Populations

    I would like assistance in selecting tests for two scenarios. I am simplifying a bit here, but basically I want to do a comparison of the percentage of patients who come in for a second appointment, comparing 2011 against 2012. 1) In the "Ideal" case, the two populations are separate. What...
  20. E

    multiple comparison of chi square tests of binary data

    Hello everybody, the code below is to illustrate how I examined the (significant) differences in certain characteristics between different regions. The data set is non-parametric so I used the Kruskal Wallis test and for multiple comparison between the regions I used the function kruskalmc. I...