(adsbygoogle = window.adsbygoogle || []).push({}); Using t-tests to get "trials until significance"?

Hi all,

I am stumped on how to achieve this with the data I have. My PI thinks there is a way, but I can't seem to find it. We want to see whether we should go ahead with this experiment or if it will take too much time.

Basically, I have 2 sets of data. I am looking to see which one conforms to a logarithmic regression line better, i.e. which one has better fit. To do that, I checked the r^2 values, and then did a t-test for unequal variance on the residual sum of squares. The difference was miniscule (p=.73).

Now, what I have at the moment is the formula for the t-test for unequal variances:

t=(xa-xb)/sqrt((sa+sb)/n)

where xa and xb are the sample means, sa and sb are the sample variances, and n is the number of trials (the actual formula uses sa/na + sb/nb, but I have the same number of data points for each set of data)

I manipulated it to show how many trials I need until t=1.96 (basically just close to significance)

n=(sa+sb)/((xa-xb)/t)^2

The issue I have with this, though, is that the means and variances could be different. How can I use this to calculate the estimated number of trials when the data I have may not be accurate? Is there even a way to do this?

Thanks for any help.

**Physics Forums - The Fusion of Science and Community**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Using t-tests to get trials until significance ?

Loading...

Similar Threads for Using tests trials | Date |
---|---|

Can a Chi2 test be used on uniform p test results? | Aug 14, 2015 |

Perfoming ANOVA test using orthogonal contrasts | Feb 13, 2015 |

Which stats test to use in this situation | Aug 19, 2013 |

Variance of statistic used in runs test | Jul 30, 2013 |

How to Test Validity using Reductio ad Absurdum | Sep 27, 2012 |

**Physics Forums - The Fusion of Science and Community**