1. H

    Which statistical approach should be used to compare healthy and sick patients?

    Hello everyone, I'm stuck trying to figure out what the best strategy is for analyzing and distinguishing between healthy and sick patients. I have a dataset that was analysed with 20 healthy and 20 sick patients (each of them is different person). I collect data using one of the...
  2. D

    Statistical Analysis for Physics Research Project

    Important concepts for Problem: Chi-Square test, p-value, Sigma Significance I am an undergraduate Physics student working on a research project which involves a certain level of statistical analysis that I have some lacking knowledge about. I have built a macro that has the capability to...
  3. S

    P-value of intercept = 0 meaning? Can age be independent var in simple regression?

    Hi I recently got into statistics... I am not too sure if this is the correct place to ask, I have included pictures as well Can I test "age of used vehicle" as independent variable against "selling price" as dependent variable in a simple linear regression? Is my residual plot as shown weird...
  4. E

    p-value for observing additional effects in chemical clusters by incorporating new chemicals in future

    I clustered chemicals based on their structural features. Later I realized that: in some clusters, there are some chemicals (not all chemicals in the cluster) that will emit red light when shined by the laser, in some clusters, some chemicals will emit green light, and in some clusters...
  5. L

    "Decreasing P-value" could be interpreted as "Getting Meaningful?" in time series?

    Hello. I'm Lee, a candidate for a master's degree in business administration in South Korea. I'm analyzing economic data in emerging markets such as Asia, And I found that many indicators are following incumbent markets such as U.S. or E.U. And the basis for that is the p-value in simple...
  6. K

    Calculating Chi-Square/Fisher exact Test with differing (sub-)sample sizes and interpreting them (retrospectively)

    I`m sorry, I realise how long this is! I tried to hightlight the questions in bold, but I don`t know how helpful it would be to ask them without providing background information first. My deepest gratitude to anybody who is still willing to read through this =) Me reading a recently published...
  7. S

    Partial Correlations with Missing Data

    I have a dataset with incomplete/missing data and want to perform partial correlations in R. I realise that pcor.test does not allow missing data and partial.r does not show p-values of correlation coefficients. Is there any other command for partial correlations that a) allows missing data AND...
  8. K

    Calculations for one-sided confidence interval

    Hello, I need help with understanding the result of µ*. Can someone show me the way to come to this result? Thank you in advance.
  9. S

    P value after Geisser-Greenhouse correction

    I have noticed that when Graphpad Prism does a sphericity correction using the Geisser-Greenhouse correction, it halves the P value for this source of variation (typically Treatments). For example, in the example I am working on, it calculates an F value of 20.25, with DF(num) = 1.391, and...
  10. H

    Generalisation of 'overlapping confidence intervals'

    I had a question about a common (possibly incorrect) trend in the medical field to look at whether two 95% confidence intervals overlap as a sign of statistical significance at the 95% level. I'm aware this is overly conservative. I've heard that 83% confidence intervals are 'better' but not...
  11. C

    Finding P-Values For a Null Hypothesis with Neutral Trend

    Please help me. I am so lost. I have data that is days above a certain temperatures every year from 1948-2019. So basically something like: 1948 36 1949 31 1950 36 1951 34 1952 36 1953 35 and so on. To find the trend I already did a least-squares linear regression and go that done. Now I...
  12. A

    What does a p-value of 0 mean in excel?

    Hi! I am in my first year of biomedical sciences and i currently am trying to write a paper about the difference in the incidence of a specific infectious disease between men and women. I am using an available dataset with the data about the incidence of the disease in a specific country. I...
  13. J

    P-Values for less than t test two sample differ by .002 when applying 1-[two-tailed-p-value] on a ti-83

    TI83 - p-values for less than t test two sample differ by .002 when applying 1-[two-tailed-p-value] So I thought that a less than p value is equal to 1-[two-tailed-p-value] but on a TI83, I see that this is not the case. The reason I need to know is I am trying to make my own calculator using...
  14. P

    How to report linear regression results (Matlab)?

    Hello, I performed a simple linear regression analysis in Matlab and am unsure about how to report the results. I definitely mention the coefficients and the p-value, but do I mention the t-statistics as well? And if so, how exactly? This is an example Matlab output:
  15. B

    Hypothesis testing

    Hey guys, This is my first thread on this forum so please bare with me as I try to be as concise as possible, I'll then write down my questions at the end of the thread. I'm working on some class notes, and stumbled upon this problem that confuses me on some point: "The drying time of a...
  16. B

    Difference between Mann-Kendall and Pearsons Correlation to obtain p-value

    Hi, I am carrying out an analysis about Vegetation and Time. I did a simple linear regression and I got the correlation between both variables (Pearsons). Now, I would like to get the significance of the data. I got the significance (p-value) carrying out "Pearsons Correlation" but my question...
  17. A

    My data does not follow a normal distribution, but Mann Whitney U test gives me a p-value of 0.935?

    As the question indicates, I conducted a normality test on Minitab, and the p-value I received was 0.018, which is less than the significance level, therefore, it is not normally distributed. Therefore, I had to conduct a non-parametric Mann Whitney U test, and the p-value is 0.935, which...
  18. A

    AMOS - interpretation of bootstrap indirect effects for one-tailed hypothesis

    Hello all, I'm testing for mediation using bootstrapping in AMOS. This method reports results for two-tailed significance, but my hypotheses are directional. With bootstrapping, significance is assessed based on confidence intervals - though a p-value is also provided. For regression, I would...
  19. M

    P-value - Parametric Vs Non-parametric

    Greetings Is it possible to compare the p-values derived from non-parametric tests to parametric tests? For example, lets say dataset 1: Copper concentration in spoil is not normally distributed, so I have to use a non-parametric test on it and get a p-value. Dataset 2: copper concentration...
  20. C

    Statistical significance

    Hi, I have the following problem and I would need some piece of advice to solve it: I have a group of 28 patients (17 survived, 11 died) and I am trying to find out if some of quantities are capable of discriminating survivors from non-survivors with a ROC analysis. For all the considered...