Projections And Confidence Intervals

Mirio De Rosa explains confidence intervals and sampling issues, using polls as an example:

Weighting is used to make sure samples reproduce the underlying characteristics of the population they are drawn from. For instance, in the UK 51.6% of voters are women, of these 22.5% are above 65 years of age, 23.1% have a higher education and so on. The people selected to make part of a sample may be recruited to ensure they match these proportions.

Within the context of weighting there are two major sampling procedures: Quota and stratified sampling. The relevant difference between them is the latter uses some sort of randomization device while with the former the interviewer decides whether or not to interview a person with certain characteristics. YouGov presumably applied Quota Sampling for the Brexit survey[4], and the gender, age and education weights they applied are shown in the following image.

Read the whole thing.

Related Posts

Tidy Anomaly Detection With Anomalize

Abdul Majed Raja walks us through an example using the anomalize package: One of the important things to do with Time Series data before starting with Time Series forecasting or Modelling is Time Series Decomposition where the Time series data is decomposed into Seasonal, Trend and remainder components. anomalize has got a function time_decompose() to perform the same. […]

Read More

Uploading Data Sets To Azure ML From R

Leila Etaati continues her series on the Azure ML R package by showing how to upload a data set: There is a function in AzureML package name “workspace” that creates a reference to an AzureML Studio workspace by getting the authentication token and workspace id as below: 1 ws <– workspace( id , auth  ) to […]

Read More


July 2016
« Jun Aug »