For the first time since The Times created Op-Ed in 1970, our space has grown. As of today, the Sunday paper will have a larger opinion section. The traditional page of editorials and letters will, as always, start off the procession, followed by the two pages you're reading right now.

The new look will include columns by Frank Rich, Nicholas D. Kristof and David Brooks, opinion articles by non-Times writers, and some very nifty layouts and illustrations. The public editor has also joined us; Daniel Okrent and his successors will be critiquing The Times, usually from the bottom of the left-hand page, on as many Sundays as they choose to write.

Happy as we are with all of this, we're aware that some readers will balk at first. Times readers have a very personal relationship with this paper. They tend to be unhappy with any change and this sensitivity reaches epic proportions when it comes to the columnists. Some of the people who've expressed delight at the prospect of Frank Rich's return to this section withdrew their endorsement when they realized that he would not continue writing for the Sunday Arts & Leisure section as well. While our columnists have a heroic amount of energy, this did seem like a bit much to expect.

And long experience tells us that readers' pleasure at getting David Brooks and Nicholas Kristof on Sunday will be mixed with unhappiness that Maureen Dowd and Thomas L. Friedman have moved to other days. There will be howls from people who have organized their reading around one favorite writer. (The last time we rearranged the columnists, in 2003, it was fascinating how many people claimed to read the paper only on, say, Wednesday.) The new schedule for the columns, including our new columnist, John Tierney, is at the bottom of this page, and we'll be running it regularly until the new becomes routine.

We've always called this section Op-Ed because it appeared in the paper opposite the editorials. Physically, that's not going to be the case on Sundays any longer. But in terms of its role in the Times opinion section, it'll still be true. Within the opinion pages, the editorials, which are now on the preceding page, have a much different aim from the rest of the package. The editorials are composed by a board of 16 people (whose names and biographies you can find on our Web site), with very specific beliefs and political views, reflecting values that in some cases the paper's editorial writers have been championing for a century. The goal is to convince you, not give you the opposition's best argument. But over in the world of Op-Ed, the editors strive to present a great range of opinion, an opportunity not only to revel in writing that reflects your own views but also to better understand alternative mind-sets.

This is not necessarily the most popular thing we do: the number of readers who call to thank us for running an article they violently disagree with is not enormous. Nevertheless, that's the agenda. The news side of the paper fulfills its mission to inform by struggling every day to provide the fairest and most impartial report possible. The opinion side is drenched in partiality, but partiality in all its stripes.

The editors at Op-Ed, led by David Shipley, search mightily for interesting and thought-provoking articles, and they're happiest when they come up with something that disagrees with our editorials. Our columnists are also chosen for their diversity of opinion - along, of course, with distinctive voices, reporting skills, passion, energy and a willingness to package it all in 700 words twice a week on deadline.

Diversity should come in diverse packages. As many of you have pointed out, we've done a better job of finding columnists with a range of interests and political opinions than with a range of genders, ethnicities or even hometowns. (The entire current team resides along the Northeast Corridor.) This is not an excuse for not doing better, but a promise to keep trying. Nobody takes criticism more to heart than professional complainers.