The chairman of each panel, in cooperation with the chief administrative official of the school district in which the teacher to be observed is employed, shall schedule observation visitations. The panel chairman shall notify the teacher, the school district, and the other members of the panel of the time and date when the observation will be made. An observation visitation shall consist of direct observation by the panel of the teacher in his own classroom situation and shall be of sufficient duration to allow the teacher to demonstrate, through the selection and use of appropriate teaching techniques, his effectiveness in teaching young school pupils. The observation shall include, but need not be limited to, the reading period. The panel, in each instance, is authorized to interview the teacher and to seek additional information through persons who have first-hand information of the pedagogical skills possessed.