Детям предлагался набор признаков,

Детям предлагался набор признаков, на основании которых нужно было угадать, какой предмет задуман экспериментатором.

Результаты (английский) 1:

Children are offered a set of grounds on which you had to guess which item is received.

Результаты (английский) 2:

Children are invited to the set of features, based on which you had to guess which object conceived by the experimenter.

Результаты (английский) 3:

Children had been offered a set of grounds, on the basis of which you want to guess what object was conceived экспериментатором.