The following studies examined the effect of probiotics on preventing allergic diseases. Place them in order from least validity or confidence, to most, according to the studies' design and other relevant factors.\ Start by clicking the first item in the sequence or dragging it here\ Drag the items below into the box above in the correct order, starting with the first item in the sequence.\ A doctor at Massachusetts General Hospital identified all at-risk patients

(1,400)

and conducted

^(+)

a randomized study, in which each patient took probiotics or a placebo, and recorded the results after 2 years. The study was double-blind (neither the researcher nor patient knew whether probiotics or a placebo were prescribed until after the results were tabulated).\ A PhD student selected 1,000 participants, asked them to choose a probiotic pill or placebo, and

^(+)

recorded results for 8 months.\ A college student asked students in his class to eat yogurt every day for a year and recorded the results. He received funding from Dannon.

The following studies examined the effect of probiotics on preventing allergic diseases. Place them in order from least validity or confidence, to most, according to the studies' design and other relevant factors