"The value of science to a republican people, the security it gives to liberty by enlightening the minds of its citizens, the protection it affords against foreign power, the virtue it inculcates, the just emulation of the distinction it confers on nations foremost in it; in short, its identification with power, morals, order and happiness (which merits to it premiums of encouragement rather than repressive taxes), are considerations [that should] always [be] present and [bear] with their just weight." — Thomas Jefferson

Writing these words in 1 821 , Thomas Jefferson could not have foreseen the remarkable advancements in science that were to occur in the future. It’s equally fair to say that were he somehow to witness the ignorance of science among average Americans today, he might despair for the republic.

Somewhere along the way, it became acceptable to admit — even boast of — one’s inaptitude for all things scientific. In its annual survey of science and engineering indicators, researchers with the National Science Foundation found that less than one-fifth of the U.S. population meets a minimal standard of scientific literacy.

One reason may be that a majority of Americans say they glean most of what they know about science from the popular press. Unfortunately, a survey of the public by the National Health Council, a health policy organization, found that 68 percent of respondents agreed with the statement, "When reporting medical and health news, the media often contradict themselves, so I don’t know what to believe."

This bodes ill in a democracy in which scientific and technological issues are growing increasingly complex. Citizens can’t make informed policy choices if they don’t comprehend the questions before them.

Herewith, then, is a beginner’s guide to interpreting science news.

  1. Science is a journey, not a destination. As wisely noted by former Harvard Provost Harvey V. Fineberg, the latest recent scientific study does not set the standard for truth, nor does it demolish all earlier findings.

  2. What’s left out of a story can be as important as what’s kept in. Always assume that any single article doesn’t tell the whole story. Reporters often face confined space in the newspaper or limited time in a broadcast, and they frequently write under deadline pressure.

  3. Journalistic "balance" is not the same as "accuracy." The mere existence of conflicting opinions in a single story does not ensure that the conclusions are factual.

  4. Not all research is scientific. Special interest groups have been known to commission not just research, but research findings to advance a cause.

  5. Science can become politicized. Universities and researchers sometimes compete for public funding. The politicians holding the purse strings aren’t necessarily expert in knowing what research most "deserves" support from a scientific standpoint.

  6. Not all correlations are causes. Just because two events occur together does not mean there is a causal link. The strength of scientific findings largely rests on how carefully researchers have controlled for other possible causes.

  7. Answers to the following questions must be obtained to evaluate the validity of any research:

  • What was the precise research question?

  • When did the research start and end?

  • Did researchers stick to the scientific method?

  • Has the research been peer reviewed?

  • How was the study performed? Was there a control group?

  • What was the sample size? Was it large enough to be statistically significant?

  • What does other research say about the subject?

If guided by time-tested principles, you don’t need a Ph.D. to distinguish between most junk science and sound science. This concern isn’t intellectual elitism: Scientific reasoning is an important underpinning of much law and regulation, particularly as it relates to public health and the environment. As Jefferson noted: "If a nation expects to be ignorant and free, in a state of civilization, it expects what never was and never will be."