factorial anova

1. 2 Way ANOVA or multiple t tests with correction?

Hi all, I am trying to do some data analysis, and I'm not sure whether to use a 2 way ANOVA or multiple t tests with Bonferroni correction. I am looking at the effect of a chemical on bacterial binding to different polymers. So for each polymer, I want to know if there is a difference in...
2. Factorial ANOVA, How to do a imple effects analysis in R?

I am running a factorial ANOVA in R. I want to find out the effect of gender and the semester the student is enrolled in on a standardized test. It is a factorial ANOVA design with two independent variables: gender (M,F) and semester when the student takes the test (1:12). The dependent...
3. Quick one please: Difference between 1-way and 2-way ANOVA - Example provided

Hello, I apologize in advance if this is too simple for these forums, but I am just wanted to be very sure. Example: A study that looks at 2 sleep treatments and their effect on 1) how long they think they slept, 2) how rested they feel, 3) how alert they are, 4) how good their sleep was...
4. (R) Analysing abundance in plots with different treatments -with factorial ANOVA?

I'm not connected to a Uni anymore, but want to write an article on my friend's data from her Master's while applying for a Phd. The data will contain 2 analyses of vegetation growth in different plots exposed to different treatments (+control). The plan is to use the sum of the plots. The...
5. Transform data for factorial two-way ANOVA/General Linear Model??

Hi, I'm not very statistically minded but I would really appreciate some guidance. I am needing to do several stat tests for my MSc dissertation. I have one dependent variable (species count) and one independent variable (year), but two species. I have constructed a basic count against year...
6. What would you do if you had two very different Values of Cohen's D?

I conducted a factorial ANOVA.. and I found a significant interaction. I used two independent samples t-tests to conduct a further simple effects analysis one group always had higher accuracy than the other group regardless of the condition. However: condition 1 had an extremely...
7. Determining sample size in a factorial repeated measures ANOVA using GPower

Hi all Can anybody tell me which F-test option in G power 3.1.9.2 is appropriate to find out the sample size for a 2x2x2 repeated measures ANOVA? The three within subjects factors are A, B & C. I am interested in finding out how many subjects I will require to find a main effect of A...
8. repeated measures factorial ANOVA post hoc test

Currently I am working on a way to distinguish Delirious patients from patients who still suffer from anesthesia and controls. I use the EEG and calculate relative powers in four frequency bands (Delta, Theta, Alpha and Beta) in three different regions (Anterior, Central and Posterior) of the...
9. ANOVA - Orthogonal Planned Comparisons

We've been given this question on a sample exam paper. An experimenter is exploring the effects of two appetite suppressants in rats. Suppressant A induces mild nausea, while Suppressant B suppresses the sensation of hunger. Half the subjects receive a low dose of one suppressant, and half...
10. which type of ANOVA?

N mineralisation is dependent variable. Management type (4 types) and position in valley (3 positions; nested in valley (with valley nested in management type [is this possible?])) are my independent variables. I want to test the affect of management type, position and interaction of both, on...
11. ANOVA One-way Vs Factorial ANOVA. Discordant results. Help

Hi everybody, I have to investigate the influence of many categorical factors (A,B,C) on a continuous response variable (Y). The procedure I'm following is: 1) Make three One-way ANOVA, every time with a different predicotor A, B, C) 2) Make all the three possible ANOVA two-way using the...
12. linear correlation between T values and coefficients for two-level factorial designs

Hi all Since I'm not sure if it is a problem of Minitab or not I decided to post this question here. I'm new in multivariate statistics and I would like to understand a possible "linear correlation" between T values and the model coefficients in two-level factorial designs. The problem is...
13. Implementing non-parametric version of 2x2 Repeated Measures ANOVA in R

Hi, I have a 2x2 repeated measures design (i.e. 1 group of participants provide data for all 4 conditions in a fully factorial counterbalanced design [so there is no time factor to worry about]). The data is non-normal so I need to use a non-parametric equivalent of the 2x2 factorial ANOVA...
14. Moderated Multiple Regression versus Factorial ANOVA.

I am analyzing an interaction effect between two continuous independent variables (Z and X) on a continuous dependent variable (Y). I have conducted both, a moderated multiple regression analysis and a two-way ANOVA (spliting each predictor at its median), obtaining different results. Using...