Travelling through time to query a BigQuery database from the past

Whilst looking into a broken Google BigQuery query recently, I chanced upon the "time travel" feature. This lets you query your BQ database to see what results it would have returned given the state of the data in the past, even if they are different to the results it now returns. I used that to … Continue reading Travelling through time to query a BigQuery database from the past

Create similar test and control groups by randomising participants with blocking in R

In the classic randomised experiment we randomly assign participants to at least two groups, test and control, by metaphorically tossing a coin to allocate them to one or the other. However, in reality sometimes slightly more sophisticated methods can be useful. One such method is blocking. Here, you first create "blocks" of participants, usually based … Continue reading Create similar test and control groups by randomising participants with blocking in R

Covid-19 testing in England’s secondary schools: the story so far

Last week, secondary schools in England reopened for all pupils, after several months of semi-closure due to the Covid-19 pandemic. During that period, most teachers were busy labouring hard to conduct their lessons remotely, often persevering with minimal extra resources and inconsistent central guidance. A smaller proportion were still going to school, in order to … Continue reading Covid-19 testing in England’s secondary schools: the story so far