# Thread: Pearsons rank bivariate correlation Help!

1. ## Pearsons rank bivariate correlation Help!

Helloooo

I am assessing the correlation between two variables;

For pearsons rank you need both variables to be of normal distribution and be continous data?

1 of my variables are median dates between two time points, there are 140 pieces of data and they are not at regular intervals.

The other variable is continous and normally distributed.

Can I use pearsons?

Thanks

Ali

2. ## Re: Pearsons rank bivariate correlation Help!

Hey squidders.

How big is your data sample? If you have enough samples then expectations (i.e. means) will have an approximate normal distribution.

3. ## Re: Pearsons rank bivariate correlation Help!

The sample size is 161.

Even if the data is normally distributed, I thought date was discrete data not continous?

Can I use pearsons as it is a large sample size?

Thanks Chiro!

4. ## Re: Pearsons rank bivariate correlation Help!

If you have enough points in the distribution, you may be able to assume continuity in the distribution.

Given you sample size I think you might be able to use the normal correlation co-efficient.

I'm basing this on the CLT where the distribution of the mean (of some arbitrary distribution) approaches a Normal distribution regardless of the input distribution.