Bias is essentially influences that could have impacted the study's results that were not accounted for in the studypic.twitter.com/RdQxn6o6wk
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
The answer to both polls is, of course, all of these things. Most potential sources of bias have many causes and indeed many impacts
Both of these sources of bias would likely make the treatment group appear better - if they did have an impact - and so reduce the strength of the study's results
HOWEVER it's important to remember that this is not true for all sources of bias What you need to look for is whether the bias applies equally to all groups, or unequally to one or more groups in the study
What do I mean by this? Well, here's an example from the recent study on carbs and health in the Lancet: reporting biaspic.twitter.com/ef2Q4Kw7Hg
We know that people under-report their food intake to medical professionals This is not surprising. No one likes to admit to their doctor that they aren't following the diet they're supposed topic.twitter.com/7MMFIzIlGe
But, AND THIS IS IMPORTANT, this reporting bias impacts every single person in the study in a similar way Thus, it shouldn't impact the results, except to potentially make them seem LESS meaningful than they actually are
If someone is bashing a piece of research, take a look at their arguments and think: "Is this really going to influence the results?" "Will it impact all groups equally?" "WHAT impact will it have?" These are all vital questions to answer
They are also important for you yourself if you want to know more about the research and its usefulness
This has been my brief thread on bias. If anyone's interested, let me know and I'll do another on different sources of bias or expand on this one
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.