Undergrad Reduced chi square for few data points

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The discussion centers around fitting a straight line to eight data points with significant error bars, resulting in a reduced chi-squared value of 0.02, which suggests a poor fit. The user questions the validity of their error estimates, which appear overly precise compared to the data spread, and seeks advice on addressing the low chi-squared value. Participants emphasize the importance of understanding the origins of the data and the role of systematic errors in analysis. There is also a concern about the user's engagement with previous discussions and the clarity of the assistance provided. The conversation highlights the complexities of statistical fitting when dealing with high uncertainties in measurements.
Malamala
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Hello! I need to make a straight line fit to 8 points, with errors on them. The data is like this ##x = [1,2,3,4,5,6,7,8]##, ##y=[377.488 691.191 , 1030.319, 1428.801, 1753.884, 2113.065 , 2398.642, 2797.664]##, ##y_{err}=[97.145, 131.452, 160.492, 188.997, 209.397, 229.840, 244.879, 264.464]##. The problem is that the errorbars (which are basically Poisson errors) are a lot bigger than the spread of the data. Hence I end up with a reduced chi-squared of 0.02. Is there anything I can do? The values of the fits are reasonable (given theoretical arguments), but I am not sure what to make out of this small reduced chi-square.
 
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Did you make a plot ?
Tell us how the data were obtained and what they represent. Especially the ##y_{err}##.
And how can you obtain such unbelievably accurate estimates of ##y_{err}##. Billions of observations, or just mindless copying calculation results ?
Are you aware of the role of systematic errors ?

BvU said:
How are the other threads going ? Long forgotten ?
I'd like to know if you understood the help given in earlier threads, or just lost interest and never reacted any more. I don't mind repeating things, but it should have a reasonable purpose.
 
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The standard _A " operator" maps a Null Hypothesis Ho into a decision set { Do not reject:=1 and reject :=0}. In this sense ( HA)_A , makes no sense. Since H0, HA aren't exhaustive, can we find an alternative operator, _A' , so that ( H_A)_A' makes sense? Isn't Pearson Neyman related to this? Hope I'm making sense. Edit: I was motivated by a superficial similarity of the idea with double transposition of matrices M, with ## (M^{T})^{T}=M##, and just wanted to see if it made sense to talk...

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