Analytics

Question

Hi!

I am completely new to both JMP and statistics and would like some help with analyzing some data (see attached file).

I work as a microbiologist and have stained bacteria from 4 different fermentations on 2 different glass slides for each fermentor. The stainings result in colored cell structures, of which I took two photos per glass slide. I now would like to know:

1) If the differences in the amounts of stained cell structures on the photos are dependent on the fermentor (A/B/C/D) or simply dependent on the glass slide.

2) If the differences in the total amount of stained structures between fermentors are significant.

How can I do this in JMP? I am very thankful for any help!

Best regards,

Ulrika

Cell staining_JMP community.jmp

Ulrika · Answer

Thank you so much @statman for your input!

I am not sure how much of a change in the response variable is of practical significance. I would prefer to see larger differences between fermentors than what I obtained :) . Thank you for the nice plot! It makes it more clear that I will probably not be able to see any differences from this experiment.

Best regards,

Ulrika

Ulrika · Answer

Thank you so much @Mark_Bailey for your help! You really made me look at my data in a different way. The counting of the colored structures from the pictures was performed manually, but the pictures were coded by my colleague to avoid any bias. The staining, resulting in the different slides, was performed on two slides at the same time from one fermentate. Then the staining of two more slides was performed, but for another fermentate and so on. Yes, the data was imported from an Excel sheet.

I will look into what you've written here, and also read up a little more on statistics. Thanks again for the help!

Best regards,

Ulrika

statman · Answer

Adding to @Mark_Bailey's excellent advice, here are some things to think about:

1. How much of a change in the response variable (Colored Structures) is of practical significance?  What is the smallest increment of change you care about or would be of scientific interest?

2. The pictures may be considered components of the measurement system.  What is done with the pictures?  How is the response quantified from the pictures?

3.  Here is a variability plot for the data set:

As you can see there is a good deal of variability within slides 4 and 8 (is this measurement error?).  This will ultimately have a large affect on any quantitative analysis.  This will also likely make it difficult to detect Fermentor-to-fermentor variability.