Um what is going on - barium sulfate fertilizer reliability (1 Viewer)

[emilios]

With the dotpoint that asks us to discuss the reliability of the fertilizer gravimetric, how come all the sources I'm reading are talking about things that influence the accuracy and validity - pretty much everything except the reliability. I thought reliability was like "reproducibility" meaning that even if your results were way off, if they were consistent among themselves then they could be considered reliable?

So then how come pretty much every source lists stuff like "barium sulfate is slightly soluble", "precise scale used", "HCl added to drive dissolution of fertilizer to completion"

 

[emilios]

bumpity

 

[Speed6]

Bump, Abdul are you there or are you sleeping, help a fellow BOSer out.

 

[Cleverusername5321]

The way we were taught was that reliability is reduced by random errors, such as ones occurring from "human error" (I hate using that term, it's way too vague). These would be unplanned errors that occur only once through repetitions of the experiment, such accidental spillage. For validity errors, on the other hand, we were taught that these are methodical errors that occur even though the experiment is repeated, for example specifying in the method that the precipitate should be dried for 1 day when that isn't enough.

https://www2.southeastern.edu/Acade...o/Error_Analysis/05_Random_vs_Systematic.html
Maybe I was wrong with my example of spillage, if going by that.

 

[faisalabdul16]

Reliability is whether or not you repeated the experiment.

Validity encompasses whether the experimental method was correct and if all variables were kept constant except for independent variable (minimising errors as well)

 

[BlugyBlug]

Reliability is whether or not you repeated the experiment.

Validity encompasses whether the experimental method was correct and if all variables were kept constant except for independent variable (minimising errors as well)

Careful. Reliability has the additional (easily forgotten) requirement that the experiment is repeated AND RESULTS ARE CONSISTENT WITH EACH OTHER. There's no point repeating an experiment a billion times and you keep getting very different values. That is not reliability.

(hope someone reads this before they go to bed before chem hsc haha).