REFERENCES
- Association for Science Education . 1976 . Science in the Middle Years , Hatfield : ASE .
- Department of Education and Science . 1983 . APU Science in Schools, Age 11: report no. 2 , London : HMSO .
- Schmidt , V.E. and Rockcastle , V.N. 1982 . Teaching Science with Everyday Things , New York : McGraw‐Hill .
- Siegel , S. 1956 . Nonparametric Statistics , New York : McGraw‐Hill .
- Williams , I.W. 1973 . “ Teaching methods in integrated science at the primary and secondary levels ” . In New Trends in Integrated Science Teaching , Vol. 2 , Paris : UNESCO .
- Wastnedge , E.R. 1967 . Nuffield Junior Science: teacher's guide, 1 , London : Collins .