Hi!
In the video, it seems to be implied that it’s the same Algorithm with different Threshold values.
However, we can use F1 for comparing different algorithms with the same threshold value as well as different algorithms with different threshold values.
Consider the following hypothetical:
Train two different algorithms on the same task.
Use F1 to find the best threshold value for both algorithms separately.
Then select the algorithm with the best F1 score overall to get the single best algorithm for the task.
Hope this was a helpful explanation!
Sam