PHILADELPHIA — State education officials denied applications for eight new cyber charter schools on Monday, citing significant deficiencies in their planned curricula, finances and overall operations.

The proposals left Education Secretary Ronald Tomalis questioning the would-be operators’ ability “to maintain a long-term, viable educational program for the benefit of Pennsylvania students.”

The state currently has more than 33,000 students enrolled in 16 cyber charters, which are publicly funded online schools. Supporters say they offer a good educational alternative to children who work best independently.

But a Stanford University study released in 2011 found Pennsylvania cyber charters performed worse in reading and math than both brick-and-mortar charters and traditional schools. And many of them are not meeting the federal academic benchmark known as “adequately yearly progress.”