"Rigorous science" means subjecting a hypothesis to the Western "gold standard" of clinical trials -- a randomized, controlled, and double-blinded trial, commonly known as an "RCT."
As an example, a simple RCT might be used to test a new medicine. Participants would be split randomly into two groups so external factors wouldn't skew the data. One would be given the medicine and the other "control group" would be given a "placebo" pill (something that looks, smells, and tastes identical to the active medicine), so that true comparisons between these groups could be made. The placebo is also used so that the participants in the study don't know which group they are in -- and their expectations won't interfere too much with the data. None of the participants or researchers knows who is in which group, a safeguard known as "double-blinding," to limit bias or cheating. Both groups would then take the pills, and the researchers would look for objective differences between the two groups to see if the medicine had been effective.
But even if an experiment is designed and executed perfectly, there are many ways in which a trial can be complicated. One is the trial size. An experiment needs to use enough participants to make sure that the study is "statistically significant" -- meaning that the findings didn't happen just by chance.
Dr. Charles Vincent, who co-wrote a book on alternative medicine research methodology, says distant healing research is a viable area of study, though it has its limits. It will never be 'gold standard' in the sense that a drug trial can be, but then neither can many forms of hands-on treatment such as surgery," says Vincent, a professor at University College London.
Though Targ's experiment follows the "gold standard," skeptics raise questions about her methodology. They say researchers will never be able to create a "pure" control group. Even if someone is assigned to a group that does not receive healing, how do the researchers prevent someone's grandmother in Texas from praying for her granddaughter and diluting the control group?
Targ says she expects that most people in the study will have a "baseline" of prayer from friends and family. She says her study is looking at whether an extreme amount of distant healing (20 weeks' worth) has any effect above the prayer the participants may already receive.
There are also questions about consistency of "dosage." With pills, the dosage in an experiment is clear. But with distant healing, how do researchers know that all the healers in the study are as effective as each other? Targ says she anticipated that question by designing her experiment so each patient receives healing from 10 different healers.
Dubious endpoints is another criticism. Are the differences being looked at between the two groups objective? Targ's brain tumor study will be more clear-cut -- comparing whether patients have died or not. But the AIDS study is looking at factors such as hospitalization in a very diverse population, some of whom are IV drug users, homeless, and smokers.
Questions like these are the major stumbling blocks for distant healing research. To explore these issues, an alternative medicine research group has been developed at the Cochrane Collaborative, an international nonprofit organization that provides scientifically sound information about health care.
"There are some challenges and flaws related to clinical trial design for alternative medicine," says Dr. Brian Berman, who heads the Cochrane Collaborative's alternative medicine group. "But you certainly can look into these things scientifically."