(August 17, 2015 at 7:05 am)Aractus Wrote:(August 17, 2015 at 5:18 am)Homeless Nutter Wrote: My main beef with the study presented in OP is this - where's the damn control group?
I want to know how happy people over 50 are, who DON'T waste what time they have left on church, community, charity, politics, nor educational courses (I mean - seriously - old people don't feel happy when they're expected to learn sh*t? Shocking...).
Or is that - somehow - not an option? Because when I turn 50 - you just watch me...
That's not how longitudinal surveys work. By definition they are surveys, not cohorts of people instructed to do different things. It would be unethical to tell a group of people not to participate in any forms of social activity for the next 20 years until the final results of the study are compiled.
But also, data obtained without the researcher modifying the behaviours or environment of the participants is the most reliable to be compared with real world data. That is, the people who were a part of the SHARE survey are completely representative of ordinary people, the researchers didn't instruct them to change their behaviours they simply observed. You really have no valid argument against the legitimate of longitudinal follow-up surveys like this, they provide excellent quality data.
Don't surveys suffer the weaknesses of self-selection and internal bias?