kaijagahm / toyModel

Modeling the impact of multiple mortality on vulture social networks. Started in Spring 2022 for Jamie Lloyd-Smith's C219B Ecological Modeling course.
2 stars 0 forks source link

How do I determine whether individuals differ consistently in their degree over time? #5

Open kaijagahm opened 2 years ago

kaijagahm commented 2 years ago

In Noa's paper "The effect of individual variation on the structure and function of interaction networks in harvester ants", she had only one network. She inferred individual variation in degree from the shape of the degree distribution--small world, normal, exponential, poisson, etc.

I can't do this because individuals' degrees change over time. When I plot multiple time series (spaghetti plot), I want to know whether there's a consistent difference between the lines, or whether they aren't distinguishable, statistically.

Noa suggests using repeatability analysis, similar to how researchers in animal personality quantify whether personality is consistent over time. She says to use the ICC, or "intraclass correlation coefficient" to do this.

For example, see https://www.datanovia.com/en/lessons/intraclass-correlation-coefficient-in-r/#:~:text=The%20Intraclass%20Correlation%20Coefficient%20(ICC,with%20two%20or%20more%20raters.

Use:

Screen Shot 2022-08-10 at 15 12 58

Intuition seems to be a good guide here. Can look at this graph and state pretty confidently that these individuals do not differ significantly in their degree. But I can't quantify that statistically.

Once I update the model to include individual variation in degree, I will want to compute the ICC for that model to see if we can actually distinguish individuals, and compare the results to this (null-ish) model.

kaijagahm commented 2 years ago

Another note: Noa says that ICC measures whether "individuals vary more over time than they differ from each other"