Experiment results not what expected

[Carrie Salinas]

I am doing an experiment on plant overcrowding. The experiment has been done, but my results do not match what I was hoping for in my conclusion. I planted radish seeds, got sprouts, but no measurable radishes!. I was going to base my conclusion on radish size and how overcrowding affects this, but now do not know how to complete my project. I am attempting to gather data in order to do my analysis and conclusions and create some sort of graphs.

How do you handle a conclusion when your results do not equal what your expectations were?

[MelissaB]

Carrie,

Unfortunately, this sort of thing can be very common in biology--organisms (whether plants or animals!) don't always behave the way we expect them to, and that can affect our experiments. But don't let that discourage you! Some of the greatest discoveries in biology have been accidental, thanks to something not behaving the way it 'should.'

Since you didn't get any actual radishes, perhaps you could measure the root volume or mass of the plants (note: this can be tricky, because you have to carefully get all the soil away from the roots and then dry them)? Or perhaps number of sprouts compared to the number of seeds you planted, or sprout height, etc.?

In general, when something goes wrong in an experiment you want to think about why it's gone wrong. Were even the less-crowded radishes too crowded? Did you use the wrong kind of soil? Water it too often, or too infrequently? If you can't do any of the things mentioned above, it's these sorts of things you'll want to talk about in your conclusions.

[deleted-71490]

Carrie:

What kinds of data did you collect? (growth rate mm/day, dry weight, plant height) Let us know rwhat you collected and we can point you to an analysis method.

Your data may tell more than you think.

Matt Mulanax

[Carrie Salinas]

I have collected data on the number of plants per tray, size of plants in both controlled and variable, number of deceased plants per group, number of leaves per plant per tray and I am now attempting to count roots (root shoots?) per plant per tray. Not quite sure how to do this or to measure root success.

Any tips for graphs, results, how to go about collecting additional data?

Thanks!

[deleted-71490]

Carrie:

One of the first things to do with the datai s make a scatter diagram where you plot the number of leaves or dead plants or root length or dry weight of plants ver the plant populations used. From these plots you willl get a better idea of your data.

Share your datqa plots with your advisor/mentor for advise.

Matt Mulanax