Abstract: The present invention provides methods for navigation in data sets that can contain non-uniform fields. In one embodiment, data sets are defined by horizontal and vertical axes, and horizontal and vertical bias lines are calculated to determine which field is highlighted in response to vertical or horizontal navigation of the data set. In response to a user's navigation, at least one bias line is recalculated. Additional axes, for example a z-axis, and corresponding additional bias lines can be implemented. The invention can be practiced as an interactive program guide for a subscription television service. The fields of the program guide may not be uniform because programs listed in the program guide may have variable start times and/or durations, or because channel information may be redundant. The invention provides more predictable navigation within an interactive program guide. By reversing navigation movements, a user returns to a previously highlighted field.