what is pseudoreplicates ??

[Vision]

Im having trouble understanding what pseudoreplicates is.

I have searched the net and couldnt find anything. Can someone point me to the right direction please.

And how would you define 'population units' I am having trouble finding definiton for these.


Thanks in Advance

[thank.darwin]

You've got me there - Does anyone know this - I would like to know to

[Thenewguy]

pseudoreplicates

I can only take a guess - pseudo is the Latin referring to false and replicates I guess would be self-explanatory, my question is in what context was this word? I remember learning about pseudopodia of single celled organisms like Euplotes of the hypotricha family. In my own studies I've found that the word pseudo is often attached to names of cellular components that at first seem to be something they are not.

Of course this isn’t an answer but perhaps a step in the right direction. You’ve certainly peaked my interest.

[DevGrp]

Its a statisical trick frequently used in phylogenetic analysis.

http://www.icp.ucl.ac.be/~opperd/private/bootstrap.html

Bootstrapping is a way of testing the reliability of the dataset. It is the creation of pseudoreplicate datasets by resampling. Bootstrapping allows you to assess whether the distribution of characters has been influenced by stochastic effects. In phylogenetic analyses nonparametric bootstrapping is the most commonly used method. The pseudoreplicate datasets are generated by randomly sampling the original character matrix to create new matrices of the same size as the original. The frequency with which a given branch is found is recorded as the bootstrap proportion. These proportions can be used as a measure of the reliability (within limitations) of individual branches in the optimal tree.

Thus bootstrap analysis:
is a statistical method for obtaining an estimate of error
is used to evaluate the reliability of a tree
is used to examine how often a particular cluster in a tree appears when nucleotides or aminoacids are resampled

So it appears to be a way of creating new replicates from a large data set and reanalysing them to check your original result?

Not that I really understand statistics.

Would a real Statistician please step forward!

[Vision]

pseudoreplicates

I can only take a guess - pseudo is the Latin referring to false and replicates I guess would be self-explanatory, my question is in what context was this word? I remember learning about pseudopodia of single celled organisms like Euplotes of the hypotricha family. In my own studies I've found that the word pseudo is often attached to names of cellular components that at first seem to be something they are not.

Of course this isn’t an answer but perhaps a step in the right direction. You’ve certainly peaked my interest.

I too have come across the word in serveral papers and the word was mainly used in a experiment, evolution, taxonomy context. Why it caught my intrest too.

From the quote by DevGrp pseudoreplicate is basically resampling your data many times to find if it is reliable which Im sure is right.

Thanks everyone for there help!