Shameless plea for help..........(Dissertation related - POWER ANALYSIS)

R.O.S.S.I · 15 Apr 2008 at 22:50

Does anybody know how to conduct a post-hoc power analysis? (to validate my chosen sample size). Just remembered my dissertation leader told me I had to include one in my work.

I've had a look through Google and can't quite seem to find one that explains how to do them in laymans terms, they're all referring to alphas and effectvalues for some reason, of which I can make no sense.

I understand some of you scorn on people asking for help with school/college/uni work, and so I'm asking you to not post in this thread if it bothers you that much.

Thanks!
ROSSI.

Lashout_UK · 15 Apr 2008 at 22:51

http://en.wikipedia.org/wiki/Statistical_power

This thing?

R.O.S.S.I · 15 Apr 2008 at 22:53

Yes, thats right, statistical power, i've had a look on there already on some of the links at the bottom that say they calculate it for you, but I dont understand what information is required.

R.O.S.S.I · 15 Apr 2008 at 22:55

Hmmm actually, does anyone know if you can conduct a power analysis when you've used a Mann-Whitney-U to analyse your data?

Archibald0 · 16 Apr 2008 at 01:32

Boy am i glad i never have to do a dissertation

Think id go bald with the stress

Voltar · 16 Apr 2008 at 02:19

Can't really help you on this sorry mate.
wiki as postd before would have been my 1st option.

Good luck nonetheless

R.O.S.S.I · 20 Apr 2008 at 20:05

Sorry to resurrect this but does nobody know how to do them? I would ask my tutor, but I don't think he would be best pleased that I skipped his lecture on it last year!

Nitefly · 20 Apr 2008 at 20:13

You need minitab pretty bad.

Sorry if thats unhelpful... but you really need that programme.

R.O.S.S.I · 20 Apr 2008 at 20:20

I've got SPSS which is the stats software we use at Uni, but you can't do power analysis in that. There is another piece of software to use with SPSS though which is for calculating power called SamplePower but it costs like 500 dollers. I've downloaded a couple of free programs but they're rather complicated!

Nitefly · 20 Apr 2008 at 20:23

CDj-Rossi said:
I've got SPSS which is the stats software we use at Uni, but you can't do power analysis in that. There is another piece of software to use with SPSS though which is for calculating power called SamplePower but it costs like 500 dollers. I've downloaded a couple of free programs but they're rather complicated!

I'm afraid I can't be of anymore help as I'm only familiar with that programme, I don't have it with me and I'm a bit rusty

I do know however its simply a case of ticking a box.

Best of luck with your dilema.

SideWinder · 20 Apr 2008 at 20:25

SPSS - have you ever used or heard of it before? I can help you if you have!

R.O.S.S.I · 20 Apr 2008 at 20:41

Yes I have SPSS. Shall I add you to msn SideWinder?

R.O.S.S.I · 20 Apr 2008 at 21:05

Bah, that didn't work. Anyone?