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This Category: > PhD Advice / Support


Found a Huge Methodology Flaw

User: rewt - 26 July 2021 17:02

Hi everyone,

I have been working on large project with several collaborating groups for the last 7 months. My part was the second stage in a 4 part process and involved me doing a methodology I have been using for the last 2 years but with a different starting material (feedstock). The results were never great because of the feedstock was not was promised to us but everything was going fine. That was until group in the next stage tried replicating my work and they found a flaw in my methodology. Simply, the detector I used was measuring an interfering particle instead of the target compound. The other method registers absolutely zero and in this scenario should be more accurate. The method I used is in maybe 20% of literature and has better signal to noise ratios than the other method but can't measure other compounds of interest. I validated method several times before using both detectors (with different feedstocks) and it worked but for some reason at the start of this project I didn't check it. I have now realised that my last 7 months worth of work is useless as I have been measuring a completely unknown compound instead. The other group using the more sensitive (and more noisy) detector cannot find of the target compound and keeps asking me methodology questions.

So does anyone have any advice after making such a big mistake? My supervisor is trying to delay admitting to it and hope the next group fixes it for us. Though we have a big meeting coming up and I don't feel I can defend my work. I just want to come out and be honest but this means my entire my contribution to the project is nil other than it doesn't work. I am stuck here trying to work out what to do and any advice or support would be welcome.

User: Nead - 26 July 2021 20:53

Hi Rewt,

This happens more than you think with feedstocks. By dector I assuming your measure gas ? can you do any validaiton now? it could be there dector either ?
Can you begin expeirmetns again ? Is there any other way to get it to work, such as increase feedstock amounts, try co-digestions etc ? Your contribution is not nil, you tried something and it didnt work, that a results in itself. If more people mention what didnt work so many people would save time and engery. I have just finshed a batch of trials for biofuels, industry partner approved the methods, results sucked and they said they tried it that way last year and results were poor so they stop- could have saving me a few months if they said it at the satrt !

Personally I would let them know what happen, explaine it work for differnt feedstocks.Let them know about the dector they might have suggestion. Also did you keep samples- they might be able to measure them for you. The purpose of these meeting is to share work but also to solve promblems etc. Your not the first person this has happen to.

User: rewt - 28 July 2021 13:53

Hi Nead,

Thankyou so much for your advice. I was spiraling on Monday and over reacted. It was nice to get some positive words then. I ended up having an informal meeting with the project lead about it and he was pretty chill. We then had another meeting with the other group members and I was surprised everyone took it as a matter of fact. We now have a plan to see what we can salvage.

The samples are liquids and I froze them after analysis. I actually have the other detector and started reanalyzing them with the other detector on Monday when I saw zero reading after zero reading. We are trying to avoid redoing too many experiments and just reanalyzing everything in my freezer.