comparison

  1. P

    sample size for control and treatment groups

    hello everyone, I am in the process of designing an agricultural experiment in which I want to compare a series of variables between a group of manufacturers who use a mobile telephone app (n=15,000) is my treatment group and another group that does not (n=100,000) which is my control group...
  2. B

    can i compare not significant value and significant value?

    situation : there are four variables, including exogenous variable x, mediator m1 and m2, and endogenous variable y. x m1 y m2 1. I did mediation analysis on two paths x --> m1 --> y x --> m2 --> y (i did sobel test) the sobel test results indicate that x>m1>y path is...
  3. S

    comparison for 2 independent groups , t test or ANOVA

    What test should i use for a comparison between two independent groups of N=30. Also if a questionnaire is made with only 2 answers like yes or no per question , should i use U Mann- Whitney or a parametric test ?
  4. S

    compare F statistics vs P-values

    Hi I have a question about comparing F statistics among effects. I have the following anova table Parameter Estimate Standard Error t Value Pr > |t| Factor1 12088.62915 2249.053598 5.37 <.0001 Factor2 -28.62915...
  5. B

    Ratio of Means - appropriate test for single or multiple comparisons? Fieller's CI?

    I would really appreciate any suggestions with the following data analysis issue. Please read till the end as the problem at first may appear trivial, but after much researching, I assure you it is not. The situation is a little complicated because I want to compare the ratios of means: For...
  6. V

    Biodiversity indices comparison between 3 sites-Which test is appropriate?

    Hi, i would appreciate some help on the following: I have to compare 3 different farming management systems (Organic, conventional, integrated) in terms of soil fauna (soil arthropod insects) I have calculated for each management system: Soil fauna's Total catches, mean abundance, Shannon's...
  7. L

    Need help interpreting regression analysis comparison results

    Hi, I am using simple linear regression analysis to compare two different population groups' development over time (one dependent variable). I am insecure about how to best interpret and report the results and hope someone could help me here. Here are the results I've got...
  8. H

    Regression calculation in Excel

    Hello all, I am new to Excel and have a question. I have a data set comprised of two groups or participants. For each participant I have 72 data points (iteration) that measure reaction time (RT). I plotted the data points on a graph and was able to insert a linear regression line and get...
  9. K

    Using multiple P-values

    I have a number of p-values from permutation tests I've done on my data. One p-value for each recording. Can I compile these values to test for overall significance?
  10. G

    Which SPSS statistical analysis to use to compare the results from two Likert scales?

    Hello, I have designed two Likert scales based on the theory of planned behaviour which argues that the purchase likelihood of a product results from the attitude towards an abstract attribute of such product. So a positive attitude should be tranlasted into high purchase intention and a...
  11. S

    Comparative study and too many variables

    Hey guys. I've been sociology for quite some time but I'm still pretty inexperienced in statistics and Stata. Here's my problem: I'm working on a comparative study between Poland and Denmark in regards to social life and education. What I'd like to do, is to compare the respondents level...
  12. D

    Get Similarity Score Between Two Columns of Data

    Hi, I've been aimlessly trawling the forums for a solution to what I suspect is a rather simple problem. I have two columns of data: Term | Paper i | Paper j --------------------------- man | 2 | 0 | park | 6 | 1 | cat | 4 | 3 | did | 0...
  13. C

    Help with ANOVA

    Hello! I'd really appreciate some piece of advice. I've just finished gathering some experimental data and i would like to draw some valid conclusions. Say i've determined the angular amplitudes of the human lumbar spine during regular movements (flexion-extension) on 10 subjects divided in 2...
  14. S

    Which method to compare models with truth?

    Hi all, Edit: First I must say sorry for the ridiculous spelling mistake in the title! I wish I could go back and change 'two' to 'to'. I have only just come across this forum while searching the net for some info - it looks fantastic so I'm hoping I'll get plenty of use out of it in the...
  15. S

    Creating histogram within variables - labels

    Hey guys. I have a dataset with 6 different job categories and a simple yes/no-answer to a question. My data is coded in two variables; job-type and yes/no. That means, that I've labeled 1,2,3,4,5,6 in Job-types with job names and 1 and 2 in answer variable to yes/no. What I don't know is...
  16. S

    Compare two variables : Ho = difference is 0

    Hello, This might be very trivial so please bear with me. A = [a1 a2 a3 a4] B = [b1 b2 b3 b4] Ho = [A-B]^2 = 0 i.e. A and B are the same. AND I also want to correct for False Discovery Rate (multiple comparisons) & report values (eg. [a3-b3]^2) that are significantly larger than 0...
  17. B

    Splus Script Assistance Needed

    Hey guys, I am fairly new to Splus and have a hopefully simple scripting request - how do i compare data cells from two different data sets and print the result? So more specifically, Data set X has 2 columns A & B. Data set Y has 1 column A and was recently created/predicted by a...
  18. F

    Examining leakage/move of cases between two cluster analysis solutions

    Hello! I am looking for the right type of analysis for the following issue. I have conducted two different types of cluster analysis on the same sample and variables. Inevitably, some cases have moved from the one cluster to the other. HOW can I observe this differences? Namely, three people...
  19. E

    Comparison of linear and power law regression models

    I'm quite a newb at statistics, with only one college-level statistics course behind me. I apologize in advance if my terminology and/or understanding are in error. My fundamental question is how do I determine whether a given dataset is better fit by a linear model or a power law model? This...
  20. X

    What test to use?

    Which statistical test would you use to analyze data from a quasi-experimental comparison Group Pre-test/Post-test? Subjects are nonrandomly assigned to the treatment and non-treatment groups. I tried searching online, and it appears that I have to use an ANCOVA? Since the statistical...