Note: A few years ago I came across the text below as part of a handout on a short course I was doing. Recently I thought that I’d link to it on my blog but couldn’t find a record of it anywhere on the web. This is unprecedented for me since I’ve always at least been able to find a reference to something I’m looking for, if not the thing itself. So as far as I can tell, this is the first time that the following text is going to appear on the Internet.
Basic, bench research study – you are testing the mechanism of an airborne viral infection on lung function:
- You have a line of carefully bred rats, all genetically identical.
- You keep them under controlled conditions of temperature, food, exposure to the environment and isolation from other rats.
- You expose them to the virus under conditions to ensure they get identical levels of exposure to the pathogen – viral concentrations and durations of exposure.
- If desired, you expose them to the virus multiple times at specified intervals.
- After an appropriate interval, you sacrifice the rats to examine the lung tissue for evidence of the effect of the virus.
If you take the same kind of study and try to implement it under the conditions of most educational research, you have something like the following:
- Your rats come from everywhere: white rats, sewer rats, pet rats, roof rats, Norwegian rats, and even a few mice. In fact, the rats are INTENTIONALLY selected to be diverse, rather than uniform.
- You have no control over where the rats live, what they eat, what they do, what other rats they consort with, or what activities they pursue.
- You expose them to the airborne virus in a large room when all the rats are gathered together by releasing the aerosol at the front of the room and letting if diffuse through the rest of the room. During this exposure interval, some rats come in late, some leave early, some are sleeping and thereby breathe in less of the virus, while others are active and breathe in more. Of course, some of the rats aren’t even there.
- If you want to have multiple exposures, some of the rats from the first exposure will now be absent, whereas other rats will be there for the first time.
- After exposure, many rats intentionally try to share the virus with their fellow rats.
- At the same time, dozens of other researchers are using the same rats for their own studies, exposing them to various agents, running them through various mazes, observing their behaviours and feeding them all manner of diets.
- Instead of holding them in controlled conditions while the virus establishes itself, you have to release them back into the wild, where they roam freely, engaging in all sorts of unexpected activities and exposing themselves to all sorts of other viruses.
- When it comes time to perform the autopsies to examine the effects of the virus, you first have to catch as many of the rats as possible. Some evade capture and other that you trap don’t look familiar to you and you question whether they are really part of the study.
- Then, you find that the ethics board denies you the opportunity to sacrifice the rats. Instead, you must develop tests to infer the effects of the virus or questionnaires to ask the rats “how they feel”.
Roland Hiss, via Larry Gruppen (University of Michigan Medical School)