Monte Carlo methods Bellman equation
Another problem specific to TD comes from their reliance on the recursive Bellman equation. Most TD methods have a so-called 



λ


{\displaystyle \lambda }

 parameter 



(
0
≤
λ
≤
1
)


{\displaystyle (0\leq \lambda \leq 1)}

 that can continuously interpolate between Monte Carlo methods that do not rely on the Bellman equations and the basic TD methods that rely entirely on the Bellman equations. This can be effective in palliating this issue.
