[R] Fwd: randomized block design analysis in R

[ONKELINX, Thierry]

Dear Alisia,

These are not very easy questions to answer without detailed knowledge
on your design. That's probably why you did not get any responses so far
(I've seen your mail pop-up several times). I would recommend that you
seek guidance with your supervisor or with the local statistician.

Have a look at the posting guide
(http://www.r-project.org/posting-guide.html). It states:

Questions about statistics: The R mailing lists are primarily intended
for questions and discussion about the R software. However, questions
about statistical methodology are sometimes posted. If the question is
well-asked and of interest to someone on the list, it may elicit an
informative up-to-date answer. See also the Usenet groups
sci.stat.consult (applied statistics and consulting) and sci.stat.math
(mathematical stat and probability).  

HTH,

Thierry

------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature
and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics,
methodology and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium
tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be
www.inbo.be

To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to
say what the experiment died of.
~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of
data.
~ John Tukey

-----Oorspronkelijk bericht-----
Van: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
Namens alis villiyam
Verzonden: dinsdag 28 juli 2009 11:28
Aan: r-help at r-project.org
Onderwerp: [R] Fwd: randomized block design analysis in R

---------- Forwarded message ----------
From: alis villiyam <aalisiyan at gmail.com>
Date: Mon, Jul 27, 2009 at 9:47 AM
Subject: randomized block design analysis in R
To: bolker at zoology.ufl.edu


Dear All user
Hello,

I'm a  student and I have some trouble with the experimental
(columns-experiments) design of my project. I use a randomized block
design with 4 treatments including a control. For each treatment, I use
3 replicates and 3 blocks.

The treatments are:

-T1 = COD (300 mg/Lit)   COD=chemical oxygen demand

-T2 = COD (200 mg/Lit)

-T3 = COD (100 mg/Lit)

-T4 = COD (0 mg/Lit) as a control

The experiment is conducted during three months and a sample is taken
each Week in every experimental unit.

At the first, I irrigated all soil columns (12 columns) with demonize
water for 1 week.

Then during 8 weeks, I irrigated all columns with waste water with
different concentration. Then, gain, I irrigated all columns with
demonize water for 4 weeks.

Now I want to know how I can analyses the results in R. For example, I
want to detect the Effect of waste water on some physical properties of
soil, before, during use waste water and after use waste water (Is there
any significant change in properties of soil.) Time is also important,
so I want to know the interaction between time and some physical
properties of soil, like water content .first comprises between
Treatments and then comprise between weeks).

Questions to be answered:

1)      Theta (water content), before (1 week) and after the COD; is
there a
difference?
2)      Theta, during, before and after the COD; is there a difference?
3)      Is there a trend in Theta, during COD (8 weeks)?
4)      Is there a difference in Theta, during COD between the
treatments?
I hope somebody can help me to find correct statistical analyses in R.


Kind regards,

Alisia

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