Dear Asim you have selected very broad area whole Punjab Province that will create so many flaws in your study because the health and nutrition status of mothers and children is not same in whole Punjab.

My suggestion to you is to reduce this area to at least to divisional level if not on district.

As for as children 6-23 months are concerned this figure you can get from the statistic department govt Punjab and at district level as it is senses dependent and there is no such formula that can give you the this figure.

Thank you Dr. Ashique,

Sir, I selected one Division Punjab purposely with rational that National Nutrition Survey (NNS, 2011) have pointed out that Sahiwal Division has the highest burden of wasting (Acute and severe Malnutrition) across the Punjab. So, my study is only focused on Sahiwal Division. Health Department or Directorate Health Punjab is using some formulas to calculate the six months, one year and five years children to allocate the OPV, de-worming medicine, Vitamin A capsule in different age categories to districts and further districts allocate to UCs. But they have no any reference and authenticity of that formula. That's why I was looking for help. I have also consulted with district statistician officers, they have also not any solution and suggestion.

Thanks again for your guidance Sir..

Your target population is already defined. What you need is a sample from that target population. As Ali says, visit government departments that keep those records, establish the number and do a sample of those numbers. If you are ding a qualitative study, remember that its the richness of data that counts. If you are doing quantitative remember it is representation that matters.

Thank you sir Kiambi. I am collecting the data through mix method (sequential experimental design). Foe quantitative data, I was interested to exactly know about my target population under investigation for selection of representative of sample. The government office has no such types of statics. I was looking some hard and fast formulas to calculate 6-23 months of children from a given population in developing countries perspective. Thank your for your answer Sir Kiambi, I will again contact to government relevant department.

Dear Muhammad Asim. If you are wanting to determe the total number of children (6-23 mos) in the area/your population for the study, can you use census data? Is that somethng the government publishes or is available elsewhere? Using births (dates) for 6 mos to 23 mos would yield the total number for your defined/selected area.

If no such census data is available, you would have to find/collect the data yourself, which might prove to be a daunting task: e.g. from hospital records of births and/or home births?

The other possiblity is to contact the Health Department or Directorate Health Punjab that you mention "is using some formulas to calculate the six months, one year, etc. and either ask for a data set or their formula.

Good luck on a most interestng and purposeful study.

Thank you so much Castanuela, your all the suggestions for determining target population is highly acknowledgeable. Thank your for suggesting hospital record or home births. It is quiet easy. Thanks again.