it is not possible to evaluate the findings. Survey methods are often misused in the popular media: big claims are made on the basis of biased and unrepresentative sample. You could discuss some specific surveys you have come across from this point of view. Activity How would you go about selecting a representative sample for a survey of all students in your school if the objective of the survey were to answer the following questions: (i) Do students with many brothers and sisters do better or worse in studies compared to those with only one brother or sister (or none)?
(ii) What is the most popular break-time activity for students in the primary school (Classes I-V), middle school (Classes VI-VIII), secondary school (Classes IX-X) and senior secondary school (Classes XI-XII)? (iii) Is a student’s favourite subject likely to be the subject taught by the favourite teacher? Is there any difference between boys and girls in this regard? (Note: Make different sample designs for each of these questions).
Aggregate Statistics: the Alarming Decline in the Sex Ratio You have read about the sharp fall in the sex ratio in Chapter . In recent decades, fewer and fewer girls are being born relative to the number of boys, and the problem has reached worrying levels in states such as Punjab, Haryana, Delhi and Himachal Pradesh. The (juvenile, or child) sex ratio is expressed as the number of girls per , boys in the age group of - years. This ratio has been falling steadily over the decades both for India as a whole and for many states in particular.
Here are some of the average juvenile sex ratios for India and selected states as recorded in the Census of and . Number of girls per , boys in the age group of - years India Punjab Haryana Delhi Gujarat Himachal Pradesh The child sex ratio is an aggregate (or macro) variable that only becomes visible when you collate (or put together) statistics for large populations.