One of the most important things while designing an intervention is to try to ensure that your study will have enough statistical power to test the hypotheses you're interested in. Picking a large enough sample is one of a variety of things to increase power. Another is block stratified randomization, of which paired randomization is the extreme.
Berk Ozler's blog
In research, as in life, first impressions matter a lot. Most sensible people don’t go on a first date disheveled, wearing sweatpants and their favorite raggedy hoodie from their alma mater, but rather wait to break those out well into a relationship. Working papers are the research equivalent of sweatshirts with pizza stains on them, but we wear them on our first date with our audience.
A piece in this week’s Nature reports that a large vaccine trial for HPV, which can cause cervical cancer, is in trouble in India due to serious violations of ethical rules and informed consent.
Last week I wrote about “treatment as prevention.” Because being treated by a combination of ARV drugs effectively prevents the transmission of HIV from an infected person to his (her) uninfected partner, the idea is that if we were to test as many people as possible, find out who is infected, and offer them ARVs, we could make significant headway in preventing the spread of HIV. In other words, test and treat.
Last month, NIAID released news that treating HIV-infected partners in mostly heterosexual HIV-discordant couples at 13 sites around the world reduced HIV transmissi
- Impact evaluation
I was circumcised in the hospital as a very young infant. Most children do get circumcised in Turkey, although I suspect that many are not as lucky as I was, including my younger brother, who went through the ordeal when he was around six years-old. I remember him in some pain and discomfort for what seemed like a long period of time to me at the time, even though it was probably no longer than a few weeks if not days…
Regardless of whether we do empirical or theoretical work, we all have to utilize information given to us by others. In the field of development economics, we rely heavily on surveys of individuals, households, facilities, or firms to find out about all sorts of things. However, this reliance has been diminishing over time: we now also collect biological data, try to incorporate more direct observation of human behavior, or conduct audits of firms.
Following on David’s rant on external validity yesterday, which turned out to be quite popular, I decided to keep the thread going. Despite the fact that the debate is painted in ‘either/or’ terms, my feeling is that there are things that careful researchers/evaluators can do to improve the external validity of their studies.