What is temporal pseudoreplication?
g) Temporal pseudoreplication occurs when multiple samples are taken from each experimental unit sequentially over time, and the sampling dates are taken to represent replicated treatments.
What is temporal pseudo replication in an experimental design?
Pseudoreplication is defined as the use of inferential statistics to test for treatment effects with data from experiments where either treatments are not replicated (though samples may be) or replicates are not statistically independent. The critical features of controlled experimentation are reviewed.
Why is Pseudoreplication bad?
Pseudoreplication leads to the wrong hypothesis being tested and false precision. Ignoring lack of independence leads to two major problems. The first is that the statistical analysis is not testing the research hypothesis that the scientist intends, in other words, the incorrect hypothesis is being tested.
How do you fix Pseudoreplication?
The two main ways of dealing with pseudoreplication are: (1) average the pseudoreplicates to obtain one value per genuine replicate, or (2) use a more sophisticated approach that captures the structure of the data where the pseudoreplicates are nested under the genuine replicates, such as a multilevel/hierarchical …
What is spatial Pseudoreplication?
Pseudoreplication occurs when you analyse the data as if you had more degrees of freedom than you really have. spatial pseudoreplication, involving several measurements taken from the same vicinity.
Why is pseudoreplication bad?
What is one way that you can avoid pseudoreplication in your experiment?
To avoid pseudoreplication all you need to do is clearly communicate your sample size. For instance: From 5 independent sites, we collected 10 samples per week, over a total of 4 weeks ( n = 10 per week, 40 per site, 200 total). Hope this helps!
How can Pseudoreplication be prevented?
What is demonic intrusion?
demonic intrusion is when you don’t know it is happening, non demonic intrusion is when you cant plan for unexpected changes in experiment therefore more replication is needed.
What’s the difference between simple and temporal pseudoreplication?
Epidemiologists recognise the same problem in terms of using the correct unit of analysis. Simple pseudoreplication is where there is only a single replicate per treatment, but subsamples are taken from each area. Temporal pseudoreplication is also where there is only a single replicate per treatment, but multiple samples are taken over time.
Can a replicate be used as a Pseudoreplication?
Ideally, one replicate from each treatment ought to be grouped together into a block, and each treatment repeated in many different blocks. Repeated measures (e.g. from the same individual or the same spatial location) are not replicates (this is probably the commonest cause of pseudoreplication in statistical work).
What is the definition of sacrificial pseudoreplication?
Sacrificial pseudoreplication is where treatments have been genuinely replicated, but either data for replicates are pooled before analysis, or the analysis incorrectly treats subsamples or multiple samples as replicates. The different types of pseudoreplication are still widespread in the literature despite some awareness of the problem.
Which is the best book on pseudoreplication?
Crawley (2007), (2005) gives a brief account of pseudoreplication. Scheiner & Gurevitch (2001) discuss many aspects of experimental design including pseudoreplication and unreplicated large scale experiments.