I have a logit model and am trying to understand and compare the predicted and observed values generated by the model. Let's say data set had 100 values and I generate all the predicted probabilities, and then I find the actual probabilities from the data set.
If I'm comparing the predicted vs observed values, I'm thinking there are two ways to do it. One is to do it value by value, while the second would be to group by the 'predicted probabilities.'
Method 1: x_value pred_val obs_val 100 0.30 0.34 102 0.33 0.36 104 0.35 0.37 106 0.40 0.40 ...
I'm also thinking there has to some way to aggregate these values. So I'm thinking of aggregating all x values where the predicted probabilities is between 10 to 20% percent, then find the avg predicted value from that range, followed by the predicted value for that range.
Method 2: Pred_probs pred_val obs_val 10 to 20% vals 0.10 0.11 21 to 30% vals 0.12 0.16 31 to 50% vals 0.15 0.30
What I'm wondering is:
When there are a large number of data points, what use is having a list of the predicted and observed values for any given value of x?
Does it ever make sense to do something as identified in 'Method 2'?