A weakness of SRR?

-Poor research deisgn may have a long term impact - Eg: Burt's research on IQ showed it is genetic, fixed, and apparent by age 11. This led to the 11+ exam which meant not all children had the same eductional opportunities -Later research shown to be based on invented evidence but the system didn't change and continues in parts of the UK today -Any SSR needs to be planned to the greatest care to ensure the findings are valid bc of the enduring effects on particular groups of people