Combining Results and Errors - A Forum Saviour!

[fasterthanjoao]

the following post probably isn't going to be so cohesive, bear with me anyway: I'm completing a report and need to combine several sets of results for the same experiment and combine their errors to give a best value - can't for the life of me remember the formulae, i know roughly what it is - sum of the squares of the values over the squares of their error, all over the square of their error...

anyway, thanks as usual!

Posting/reading on this forum should become compulsory for all undergrads, its helpful.

 

[Meir Achuz]

For values y_i with errors d_i:
<y>=Sum[y_i/d_i^2]/Sum[1/d_i^2].
The resulting error is 1/D^2=Sum[1/d_i^2].

 

[kyle8921]

Hello there,

I completely understand your struggle with remembering the formulae for combining results and errors. I can assure you that this is a common issue and there are ways to overcome it.

Firstly, it is important to have a good understanding of the underlying principles behind combining results and errors. This will not only help you remember the formulae, but also allow you to critically evaluate your results and identify any potential errors.

In terms of the formulae, you are on the right track with the sum of the squares of the values over the squares of their error. This is known as the weighted mean, where the weight is the inverse of the square of the error. It is a good idea to write down the formula and practice using it with different sets of results and errors.

Additionally, there are other methods for combining results and errors, such as using the standard deviation or standard error. These methods may be more suitable depending on the type of data you are working with. It is important to understand the differences between these methods and when to use each one.

I am glad to hear that you find this forum helpful. As scientists, it is important for us to share our knowledge and experiences with others. I would also encourage you to seek help from your peers and professors if you are still struggling with combining results and errors. Working together and discussing different approaches can greatly improve our understanding and problem-solving skills.

Best of luck with your report and I hope this helps you in your future experiments as well. Keep up the great work!