1. A method for selecting a structure to represent tabular information, the method comprising: selecting, corresponding to a table, a table structure from a collection of table structures, a table structure function describing when cells in a cell-pair in the table structure should be similar to one another, the table being a part of a corpus of a question and answer system (Q&A system) wherein the Q&A system uses the corpus to answer a natural language question; selecting a cell similarity function, wherein the cell similarity function compares the cells in the cell-pair in the table structure and outputs a probability that the cell-pair includes cells that contain values that are similar to one another according to a criteria; determining a cell similarity probability of a first cell and a second cell in a first cell-pair in the table structure being similar to each other according to the cell similarity function; adjusting a computed probability of the table structure representing the table using the cell similarity probability; and indicating the computed probability as a probability of a first model representing the table, wherein the first model is a function of the table structure and the selected cell similarity function.