As most science journalists know, a singe medical study doesn't mean much; systematic reviews and meta-analyses, which compile the evidence from many studies, are more meaningful. But not all meta-analyses are created equal and the genre is growing rapidly: More than 10,000 such studies were published in 2018. Are we able to critically read and interpret meta-analyses? Can we tell a solid review from a sloppy one? And what to do when different teams end up fighting over conflicting meta-analyses, which recently happened in the fields of antidepressants, chronic fatigue syndrome, and the link between gaming and aggression? During this crash course, you will hear from leading experts how good meta-analyses are done; learn how to interpret their outcomes; and get the tools you need to report on them as a critical science journalist.