Modify the experiment design

Once the data-input process is complete, the data are analysed producing a total variance for the specified design.  This section of the software provides the user the opportunity to estimate the effect of modifying this design on the expected total error of the experiment.

There are three main elements to this part of the software:

1. 1)Manually modifying the replicates structure of the experiment
   

2. 2)Costing the experiment
   

3. 3)Automatic calculation of the optimal sampling plan
   

These are covered in more detail below.

If necessary, it is possible to return to the data-input section at any time by clicking the section 1 banner at the top of the user-interface.  Doing so will reset the experiment design to reflect the structure of the input data.

Replicates at each level can be manually altered using the +/- buttons and the text-boxes under the tree-display.  PowerNest will automatically calculate the expected effect on the total error of the assay based on the new design.

Manually modifying the replicates structure of the experiment

Costing the experiment

Specifying the financial cost of performing a replicate at each level allows the software to perform a simple calculation to determine the total cost of the currently displayed experiment design.

Automatic calculation of the optimal sampling plan

The calculation of the optimal experiment design requires only the replicate costs at each level and the maximum budget of the experiment.  PowerNest will use the error and costing information to search all possible experiment designs, returning the design with the smallest error at the lowest cost.  This design will be displayed in addition to the calculated cost and expected error.  The user can still manually modify this design if any adjustments are necessary.

PowerNest allows the user to specify their preferred number of replicates at each level of the design.  This is not mandatory but can be useful in situations where, for example, the investigator has access to a set number of subjects or prefers to run triplicate PCRs for each RT.  To specify a desired number of replicates, enter the number in the text-box to the right of the text-box specifying the cost at that level.  Enter a ‘0’ into the box to specify no preference.