This survey focuses on the recent (after 1998) developments in
the area of derandomization, with the emphasis on the derandomization of
time-bounded randomized complexity classes.
We study the complexity of representing polynomials as a sum of products of polynomials in few variables. More precisely, we study representations of the form $$P = \sum_{i = 1}^T \prod_{j = 1}^d Q_{ij}$$
such that each $Q_{ij}$ is an arbitrary polynomial that depends on at most $s$ variables.
