Adoption touches two of our most basic human concerns: identity and family. So it's proper that children's books about it should be truthful, not just careful.

Most of the adoptees in the children's books reviewed here wonder who their parents were and why they "gave them up." They've been hurt by the blunt, complacent questions and teasing of their classmates. They're deeply conscious of being special. Yet these are conciliatory books about generally happy, "chosen" children and adolescents. Their stories -- whether light or dark -- are wonderful to read.

*How It Feels to Be Adopted, by Jill Krementz. Knopf; $11.95; ages 8 and up.

Krementz gathered this collection of testimonials and photographs to give adoptees a voice in the debate about adoption. The book was also meant to affirm the thoughts and feelings of young adoptees.

"Finding the families for this book was not easy," Krementz tells us. "Adoption is still a subject that makes many feel uncomfortable."

But 19 diverse children, ages 8 to 16, did come forward. In smoothly edited transcripts, they talk about their birthdays, foster families and moments of anger, pride and fear. Though loyal to their adoptive parents, most agree with Krementz that more information about their backgrounds should be available to them.

Well known for her photography, Krementz has included one or two shots of each young speaker and one of each family. The family portraits are faintly repetitious. The portraits of the adoptees alone, however, are as varied and compelling as the children themsleves. This book glows with their humanity.

*We Don't Look Like Our Mom and Dad, by Harriet Langsam Sobol. Photographs by Patricia Agre. Coward-McCann; $9.95; ages 5 to 10.

Although the Levins "live together and play together," they are not a typical family. "No one in the family is biologically related to any of the others."

Some of the photographs of this Caucasian couple and their two Korean-American sons, Eric and Joshua, ages 10 and 11, are displayed on the diagonal to make the book resemble a family album. Family life is a dominant theme, but we also see the boys as individuals and with friends. Being adopted is often perplexing to them, yet the boys appear just as concerned with playing soccer, going to school and learning the cello. They lead active, well-rounded lives.

As in their other photo essays, Sobol and Agre work well together, combining visual and verbal details to give an impression that is both sensitive and candid.

*So You're Adopted: A Book About the Experience of Being Adopted, by Fred Powledge. Charles Scribner's Sons; $9.95; ages 12 and up.

Long ago, Powledge tells us, the Babylonians treated adoption as an irrevocable act. Although we still do, the biggest issue facing adoptees today is whether to search -- and when, why, and how to search -- for one's biological parents. Although national statistics about adoption are hard to come by, Powledge believes this is "the best possible time in our history to be an adopted person," and he dispels several myths. Most adoptions, for instance, occur between relatives rather than strangers.

Tracing historical changes in adoption, Powledge shows how agencies shifted their focus from parents to children during the 1950s. Then, in the 1970s, the stereotype of the most desirable child as white, healthy and very young also changed.

Perhaps the greatest change has been the growing acknowledgement that adoption should be studied and discussed. Himself an adoptee, Powledge interprets his evidence in the most reassuring light.

*Karen's Sister, by Elisabet McHugh. Greenwillow, $9.50, ages 8 to 12.

This is an enjoyably frank story about Karen, a 10-year-old Korean-American girl whose mother decides to adopt a second child. When Meghan, also Korean, arrives, she looks "really tiny and thin, and . . . about to throw up." Her adoption provides Karen with a chance to reflect on her own adoption.

"If you are wondering about my father," Karen says to the reader, "I don't have one." She does, however, have a companionable relationship with her mother, a veterinarian who is young and has never married. Karen is sure that her mother depends on her for everything from "a decent meal" to "clean socks." This feeling of interdependence has made her confident enough to joke about being sent back to Korea. It also makes her a caring sister.

What is zesty about the book is the conflict between Karen's mother and Karen's grandmother, an outrageously feminine woman who nags her daughter to "catch a husband." Karen's grandmother is sexist, underhanded and complaining, but she is also a loving force.

Both Karen and Meghan have joined a family that is imperfect and funny to read about. It isn't surprising to learn that their creator, Elisabet McHugh, is herself the single mother of adopted children.

*The Finding, by Nina Bawden. Lothrop; $10.25; ages 8 to 12.

Nina Bawden, a British writer, is widely admired for her complex characters and satisfying plots. In this book, like her others, the children are highly individualized. And although Laura, 13, and her brother Alex, 11, seem immature, they are otherwise convincing.

"No one knew where Alex came from. Only where he was found," the story begins. Alex's mother tells him that being found in the arms of a statue near the Thames makes him "special," and Alex, safe in the love of his adopted family, agrees.

Specialness has two sides, however, and Alex's mysterious past returns to haunt him in the form of an implausible inheritance. The frightening urban adventure that follows is somewhat abrupt -- but the story is exciting, and happily resolved.