In this paper, we compare the search effort of the word conditioned and the time conditioned tree search methods. Both methods are based on a time-synchronous, left-to-right beam search using a treeorganized lexicon. Whereas the word conditioned method is well known and widely used, the time conditioned method is novel in the context of 20 000-word vocabulary recognition. We extend both methods to handle trigram language models in a one-pass strategy. Both methods were tested on a train schedule inquiry task(1 850 words, telephone speech) and on the North American Business (Nov.'94) development corpus (20 000 words).