2020

December

• How to make plots with factor levels below the x-axis (bench-biology style)

November

• What is an interaction?
• How to estimate synergism or antagonism

October

• Type 3 ANOVA in R -- an easy way to publish wrong tables
• Linear models with a covariate ("ANCOVA")
• Normal Q-Q plots - what is the robust line and should we prefer it?

July

• ANCOVA when the covariate is a mediator affected by treatment

June

• Bootstrap confidence intervals when sample size is really small

May

• What is the consequence of normalizing by each case in the control?

April

• Melting a list of columns

March

• Analyzing longitudinal data -- a simple pre-post design

February

• Using Wright's rules and a DAG to compute the bias of an effect when we measure proxies for X and Y

2019

November

• "Nested" random factors in mixed (multilevel or hierarchical) models
• Estimate of marginal ("main") effects instead of ANOVA for factorial experiments

October

• Can a linear model reproduce a Welch t-test?
• Normalization results in regression to the mean and inflated Type I error conditional on the reference values
• A comment on the novel transformation of the response in " Senolytics decrease senescent cells in humans: Preliminary report from a clinical trial of Dasatinib plus Quercetin in individuals with diabetic kidney disease"

August

• What is the consequence of a Shapiro-Wilk test-of-normality filter on Type I error and Power?

July

• What is the bias in the estimation of an effect given an omitted interaction term?
• Is the power to test an interaction effect less than that for a main effect?

June

• Analyze the mean (or median) and not the max response
• Paired t-test as a special case of linear model and hierarchical (linear mixed) model
• What does cell biology data look like?
• Reanalyzing data from Human Gut Microbiota from Autism Spectrum Disorder Promote Behavioral Symptoms in Mice

May

• GLM vs. t-tests vs. non-parametric tests if all we care about is NHST -- Update
• Should we be skeptical of a "large" effect size if p > 0.05?

April

• Blocking vs. covariate adjustment
• The statistical significance filter
• Covariate adjustment in randomized experiments

January

• What to write, and not write, in a results section — an ever-growing list
• Paired line plots
• GLM vs. t-tests vs. non-parametric tests if all we care about is NHST
• Expected covariances in a causal network

2018

December

• Compute a random data matrix (fake data) without rmvnorm

November

• Reporting effects as relative differences...with a confidence interval

October

• Interaction plots with ggplot2

September

• Textbook error 101 -- A low p-value for the full model does not mean that the model is a good predictor of the response
• A simple ggplot of some measure against depth

May

• Should the model-averaged prediction be computed on the link or response scale in a GLM?
• On model averaging the coefficients of linear models
• An even more compact defense of coefficient model averaging
• Model-averaged coefficients of a GLM

April

• On alpha

March

• Combining data, distribution summary, model effects, and uncertainty in a single plot
• What is the range of reasonable P-values given a two standard error difference in means?
• Bias in pre-post designs -- An example from the Turnbaugh et al (2006) mouse fecal transplant study
• What is an R doodle?