anova

1. Why does the “linear regression t-test” return a p-value (two-tailed) from regression that is twice the p-value from ANOVA? (Binary predictor)

I'm using the "linear regression t-test" guide at https://stattrek.com/regression/slope-test.aspx The guide shows calculating t =b1/SE, where b1 and SE are provided by the regression function (here lm() - using R.) The guide shows the p-value gets doubled as this is a two-sided test...
2. Help on data correctness for ANOVA

Hello friends, My aim is to study the nature of length of stay of vechicles in a parking lot. A day is split to 3 sessions namely Morning - 10am to 2pm, Afternoon - 2 pm to 6 pm, Evening 6pm to 10pm. Given the In time and Out time of a sample size of 9000 vechicles, I need to statistically...

I am conducting research on the effects of social media usage (frequency of checking and duration) on body image and self esteem n = 264. Every ANOVA is not significant :( however Boxplots have revealed a good number of outliers. When I removed 5 "moderate outliers" (between the mild and extreme...
4. I need advice; Correct statistical model in preclinical experiment

Hi all, I made a specific preclinical experiment to test an effect of new drug on memory. I used water maze test (behavioral test based on learning and orientation in space) with 4 groups of animals (each group n=7), 3 different treatment groups and 1 saline group. I measure three values; time...
5. What kind of statistical test would I use for this experiment?

Hi there, I'm sorry I'm still very new to this platform and am generally clueless about statistics. This may be a little long winded, but I'd really appreciate any help! I have two groups of organisms, all of the same species but from two different habitats, labelled "group 1" and "group 2" as...
6. Appropriateness of using ANOVA on PC-scores (PCA)

Hi everyone, I'm new to the forum but wanted to ask a question about the appropriateness of using a test such as ANOVA or Mann-Whitney U test on the PC-scores of a Principal Component Analysis. I have recently received the critique on a submitted manuscript that it is problematic that I did...
7. Help with my research question analysis

Hi everyone, I am a doctor working on a project investigating an intervention we have been using in the intensive care unit in my hospital for treating Covid patients. I am collecting data on all the patients who have been admitted and look at whether they have had this intervention, whether it...
8. I don't know whether I'm doing ANOVA right!!

I want to find the significant difference between two groups (1 and 2). As my teacher said I should use anova. but i dont know whether i'm doing that right or not. so these are the percentages: 42.3 44.2 57.6 60.1 66.2 22.6 36.8 58.3 71.6 91.8 the first 5 ones are group 1 and the rest are group...
9. Testing for similarity between countries

For my thesis, I am looking at the effect of environmental controversies on the profitability of Chinese and European firms. As part of my exploratory analysis, I have to check whether or not the European countries are similar enough to consider them as 1 group. I collected data on economic...
10. Comparison Between Three Groups Over Time

Which statistical test should I use to compare between three groups over time (28 days) using means calculated for the whole group?
11. [ANOVA in R] Which ANOVA to run?

Dear forum members, I have been looking for a solution that fits my analysis both on this forum and the web and have returned empty handed so decided to post my own thread. For my Master's thesis, we have performed an experiment with 160 plants from 10 different genotypes, divided in 2...
12. What test should i use? THESIS HELP!!

Hi, I am currently studying Zoology at university. I am currently in my final year conducting my dissertation. I have completed my data collection and I am now on to my statistics. My dissertation looks at the relationship between light intensity and growth rate in marine sponges. I have 5...
13. One way ANOVA or Two Way ANOVA?

Hi all. I was given this assignment and asked to analyse the data (5% level of significance). Should I be using two one-way ANOVAs to compare the effect of preservative and days (independent variables) on the bacterial count (dependent) separately? Or should I be using a two-way ANOVA to...
14. What Statistical Treatment can I use in this type of data?

We are currently conducting a small study and have very small background in Statistical Analysis. We conducted some experiments and have gathered some data. Can anyone help me in identifying what type of Statistical Treatment we can use for this? The second column pertains to the number of...
15. Intepretation of Results

Can someone help me interpret the following results or tell me how i can do it ? Need to explain these results in my thesis. I would be really thankful for any kind of help.
16. Could someone explain "sphericity in ANOVA" for me, please?

Hi! Could someone explain "sphericity in ANOVA" for me, please? I am a complete dummy, so I need a "for dummies-explanation". I would be very grateful for the help. All the best!
17. Choosing the best ANOVA

Hello, I have this data set and I have quite some trouble choosing and running the best ANOVA to deal with it. There's a 2x2 design: testing if people who are blind have better hearing than people with normal vision, and whether this is influenced by the type of sound. The data are thresholds...
18. Independent, non-normal, unbalanced, analysis of an interaction effect

I have previously used straightforward two-way ANOVAs for comparing bone density across sport disciplines. I have males (M) and females (F) across low impact (LI) and high impact (HI) sports (N = 92). I have 24 males and females in in the LI group, 19 females in the HI group, but 39 males in the...
19. Marketing research project - ANOVA or Chi Square test?

Hi everyone, I'm currently doing a marketing research project at university. It requires me to create a survey on Qualtrics and to then collect and analyze the data with SPSS. The project also absolutely requires that I use the following statistical tests: I. Chi square test for independence...
20. Two continuous variables (scores), one categorical variable (gender), how to test?

I want to compare OCD scores (continuous variable) to PTSD scores (continuous variable), by gender (categorical). Basically I want to know whether OCD scores depend on PTSD scores and gender. What can I use for this? I know I can't use two-way ANOVA because I have one continuous independent...