Hey pollsters! Poststratify on party ID, or we’re all gonna have to do it for you.

Alan Abramowitz writes: In five days, Clinton’s lead increased from 5 points to 12 points. And Democratic party ID margin increased from 3 points to 10 points. No, I don’t think millions of voters switched to the Democratic party. I think Democrats are were just more likely to respond in that second poll. And, remember, […]

The post Hey pollsters! Poststratify on party ID, or we’re all gonna have to do it for you. appeared first on Statistical Modeling, Causal Inference, and Social Science.

His varying slopes don’t seem to follow a normal distribution

Bruce Doré writes: I have a question about multilevel modeling I’m hoping you can help with. What should one do when random effects coefficients are clearly not normally distributed (i.e., coef(lmer(y~x+(x|id))) )? Is this a sign that the model should be changed? Or can you stick with this model and infer that the assumption of […]

The post His varying slopes don’t seem to follow a normal distribution appeared first on Statistical Modeling, Causal Inference, and Social Science.

Avito Duplicate Ads Detection, Winners’ Interview: 1st Place Team, Devil Team | Stanislav Semenov & Dmitrii Tsybulevskii

Avito Duplicate Ads CompetitionThe Avito Duplicate Ads Detection competition, a feature engineer’s dream, challenged Kagglers to accurately detect duplicitous duplicate ads which included 10 million images along with Russian language text. In this winners’ interview, Stanislav Semenov and Dmitrii Tsybulevskii describe how their best single XGBoost model scores within the top three and their simple ensemble snagged them first place.

Postdoc in Finland with Aki

I’m looking for a postdoc to work with me at Aalto University, Finland. The person hired will participate in research on Gaussian processes, functional constraints, big data, approximative Bayesian inference, model selection and assessment, deep learning, and survival analysis models (e.g. cardiovascular diseases and cancer). Methods will be implemented mostly in GPy and Stan. The […]

The post Postdoc in Finland with Aki appeared first on Statistical Modeling, Causal Inference, and Social Science.

Balancing bias and variance in the design of behavioral studies: The importance of careful measurement in randomized experiments

At Bank Underground: When studying the effects of interventions on individual behavior, the experimental research template is typically: Gather a bunch of people who are willing to participate in an experiment, randomly divide them into two groups, assign one treatment to group A and the other to group B, then measure the outcomes. If you […]

The post Balancing bias and variance in the design of behavioral studies: The importance of careful measurement in randomized experiments appeared first on Statistical Modeling, Causal Inference, and Social Science.