significance test

  1. F

    How to calculate statistical significance for Cost of Sales

    Hi there, I work in ecommerce and we do a lot of AB testing. I am testing 2 populations, and wanted to prove whether sample A has a significantly lower cost of sales vs. sample B [note: cost of sales is calculated by cost / sales i.e. if you spend £20 and got £100 sales, then the cost of...
  2. A

    How can evaluate the significance of unbalanced variables?

    We have a questionnaire which has a question with three options: "a", "b", and "c". All participants are allowed to choose one of these three options. "a" represents the condition "X" and, "b" and "c" both represent the condition "Y". Our goal is to compare the condition "X" with the condition...
  3. E

    Event study - varying sample size per event window allowed?

    Hi all, I am conducting an event study, analyzing how social media posts are affecting stock prices. Is it statistically allowed to have a different number of observations per event window? E.g. to have in event window [0;1] 120 observations for which the abnormal returns are analyzed...
  4. A

    Statistical test for comparing percentage not mean

    Hi, I am wondering what test should I use to compare two percentage value from two different observations. Let's say I have a damage of crop 15% versus 2% in control, is there a ways to statistically test the significance between the two values? Not sure if this make sense statistically...
  5. J

    Event Study: T-Stat for Cumulative Abnormal Returns

    I am performing an event study using the market model theory. Rit = αi + βiRmt + εit With Abnormal Returns(AR) ARiτ = Riτ − αi − βiRmτ. So to test the significance of the Cumulative Abnormal Return's(CAR's), one must calculate the variance of the aggregated AR's across firms and then sum...
  6. J

    Which test to determine if statistically significant

    What test can I use to determine if a result is statistically significant, see screenshot: https://www.screencast.com/t/y5z9SpFtW. 5% of the orders generate 8% of the revenue for a specific channel, but the order count is small (under 30). I'd like to determine if the channel performance is...
  7. G

    Multinomial regression: how to interpret results

    Hello Everyone, I'm currently writing my master's dissertation and i'm having two main issues. 1) The first one is related to the attached picture: as you can see, both the variables "deal value" and "N employees" are signicative, but the B and the Exp(B) are zero. This way they are not...
  8. C

    How to show statistical significance of one choice in a 4 choice question?

    Participants are shown a video of two performers. They are then asked to select an option from the following 4 choices: 1. Performer A exhibits emotion. 2. Performer B exhibits emotion. 3. Both performers exhibit emotion. 4. Neither performer exhibits emotion. My responses are about 0%...
  9. D

    Significance test for 13 dichotomous DVs?

    I am studying unprofessional conduct. I have every case of misconduct over a 5-year period. I am curious if misconduct varies by education level. As you can see, misconduct is broken into 13 mutually exclusive categories, with a binary coding scheme. Theoretically, all 13 charges could exist...
  10. M

    Which statistical test to use? Compare 5 categories with data (ratio scale)

    Dear all, I desperately in need! I have two samples (reports of 30 good and 30 bad companies). For each sample I classified statements in five categories (one being the "best" category, five being the "worst" --> ordinal scale). Within the categories, I have absolute frequencies. One example...
  11. J

    Time series

    Hello, I have a question about time series. I have two time series (very similar, they differ just due to the minor calculation method) and I wonder if there is some test to verify if these two time series are statistically significantly identical (equal). I tought about the two-sample...
  12. I

    How to test Accuracy significantly different from chance?

    Hi All, So I have more than 60 subjects who participated in an experiment. I would like to exclude those who performed at chance level. The problem is where should I set my cut off? Is 55% not chance? And 57? So my prof said I should test if the suspect cases significantly differ...
  13. M

    Number of Clients at 2004 vs 2012 Significant test

    HI Guys, I have a data-set of health centers. I have a variable that counts the number of clients the center served. I want to see if the centers increase significantly the number of clients served from 2004 to 2012. I have the same agencies for all the years. What would be the correct test...
  14. H

    multinomial distribution and degrees of freedom

    Hi I have some data from a housing survey (sample size 13,500) and have found that the proportion of privately rented housing is slightly higher than the proportion of social housing. i want to test if the proportions are different. I found some advice at the link below indicating that I must...
  15. E

    Interpreting similarity coefficients

    I am interested in finding out a good measure of similarity to determine if two sets are significantly similar to each other. I know there are many different similarity coefficients, like Jaccard Index, Dice Coefficient, Cosine Similarity, Simple Matching, etc. My problem is how to interpret...
  16. 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...
  17. M

    95% Confidence Interval for Regression Coefficients Question

    Hello all, I have been trying to figure out how to answer these homework questions for far too long and happened upon this forum with hopes that I could get a nudge in the right direction…Here is the problem as an attachment. Also included is my work thus far…I think my issue is...
  18. E

    Most appropriate statistical test for this nested design

    I currently am conducting a study where I have three variables: one that is binary, and two numerical variables as measured on a ratio scale. Each of the subjects in my study has values for each of the three variables. Variables: Condition (binary): Values 0 and 1 Pre (ratio) Post...
  19. F

    [R] Difference between regression lines significant?

    Hi, I'm a PhD student researching processes of technology maturation. For this purpose I collected patent data which I want to use to differentiate between 3-6 yet arbitrary maturtiy phases (e.g. technology introduction, growth, maturity, decline). For several different technologies I have...
  20. H

    (Using R) What’s the right test to compare for significance?

    First of all, many thanks for looking at this post. My problem is partly technical knowledge (or lack of), but mainly one of perception! I’ve been searching the web, looking at forum posts, help files, etc, but can’t quite get my head around the issue to come up with a satisfactory answer...