[Stoves] RESEARCH PROPOSAL

[IPC]

Dear Gloria

It depends on what accuracy you want from your results.  You presumably want
to be able to say, with reasonable confidence, that the group using stove A
has more (or less)of a property than the group using stove B.  If the
property is reasonably normally distributed, then a sample size of 35 will
give you a relative standard deviation of around 10%, which may well be too
big to enable you to differentiate between the two groups. You may land up
with results that look like 65 +/- 15 and 70 +/- 15 at the 90% confidence
levels and you won't be able to say definitely which is better, because
statistically there is a high probability that the two are the same.  

It is for this reason that we tend to go for samples of 100 or greater, when
the averages have lower standard deviations.

Hope that helps.

(Dr)Philip Lloyd
Energy Research Centre
University of Cape Town
Private Bag Rondebosch 7701
South Africa
Tel +27 (0)21 650 3896
Fax +27 (0)21 650 2830
e-mail philip.lloyd at uct.ac.za 

  

-----Original Message-----
From: stoves-bounces at listserv.repp.org
[mailto:stoves-bounces at listserv.repp.org] On Behalf Of Gloria Chaonamwene
Sent: 12 November 2007 09:57
To: crispin at newdawn.sz; Discussion of biomass cooking stoves
Subject: Re: [Stoves] RESEARCH PROPOSAL

Dear friends

I am in a process of writing a proposal (Masters degree) on indoor air
pollution and stove performance.  What I want to do is to conduct a cross
sectional study of stove performances.  Two communities will be selected and
the results to be compared and analysed as such. As per sample size, I am
debating whether to have 35 each community or less (just pilot).  Since I am
a new candidate in these issues, I thought of consulting the experts from
this forum to guide and to assist on how the research proposal can be best
structured.

Very much interested to improve stove performances in Malawi since 98%
depend on biomass fuel.

Gloria Chaonamwene


----- Original Message -----
From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
To: "'Discussion of biomass cooking stoves'" <stoves at listserv.repp.org>
Sent: Monday, November 12, 2007 1:35 AM
Subject: Re: [Stoves] newcomers


> Dear Cornelio
>
> I agree with your approach.  I found the most effective way to talk 
> about air supply, esp the secondary air and the important of limiting 
> excess air to increase thermal efficiency, is to talk for a short time 
> with a blackboard, then to light a representative stove and watch the
fire.
>
> As the discussion progresses, the technologies can get more complex 
> and
the
> fire better understood.
>
> I think that can be done on the website with one page chats and 
> pictures, followed by a short movie demonstrating what is being talked
about.
>
> A major problem faced with artisanal production of stoves is design 
> drift and if the artisan knows why things are the way they are, they 
> are not likely to produce functional stoves.
>
> Regards
> Crispin
>
>
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