The increased contact some children may be having with their fathers "easily has been offset by the decreased contact others have if their parents don't stay together," reminds University of Pennsylvania sociology Prof. Frank Furstenberg.

The distancing of noncustodial fathers from their children, he says, usually occurs some time after the parents' separation. A recent study conducted by Furstenberg and an associate indicates "a transition stage for some outside parents between a period of intense involvement and a greater degree of disengagement."

Among other points raised by Furstenberg's study:

Where parents have separated and/or divorced, a near-majority (49 percent) of the children involved had not seen their noncustodial parent over the preceding 12 months, "and only one child in six averaged weekly contact or better."

The noncustodial father's relationship with his children most often is "social or recreational" and involves little or no caretaking responsibilities. "Outside fathers who socialize with their children at all usually do so from a distance and with a great deal of laxity. There seems to be more than a grain of truth to the stereotype that parents outside the home behave more like pals than parents."

Few children ever sleep over with their noncustodial fathers and, suggests Furstenberg, "probably a majority have never set foot inside the houses of their nonresident fathers."

Noncustodial mothers (about 5 percent of the noncustodial-parent population) generally maintain a closer relationship and take a more active role in childrearing responsibilities.

Noncustodial parents, "fathers in particular," often shift their caretaking responsibilities to second families, that is, they "exchange one set of children for another as they move from one household to the next."

Noncustodial fathers sometimes do become more involved with their children after they reach late adolescence or early adulthood, and have moved out of the custodial parent's household.