# sample design

1. ### Simple Random Sample vs. Population?

I'm a little confused about whether or not I need to use a simple random sample in a problem. In order to justify his style of teaching, Professor X is trying to evaluate whether or not students who take his Math 101 course are more likely to continue to the next semester than students who...
2. ### Call Centre Strategy

Hi, I'm working on a research project for a call centre, it's been a while since I have done any applied statistics so I could really use some help. Here's what I want to do: I need to understand why customers are calling into the call centre so I can design an appropriate queuing and...
3. ### Sampling Plan Help

Hi! I'm new to the forum. Hopefully this is the right place to post for some assistance. I have a business partner that asked about control charts, but I think he is looking more for an acceptance sampling plan. I have done this in the very distant past, but it's just been too long... :(...
4. ### How I can use this sample size calculation formula

Hi Everyone, Hope you are doing well! I am launching a refugees and asylum seekers profiling exercises with the main objectives to determinate their poverty prevalence based on food and non food expenditures poverty line. I have 9670 households (targeted population) setted in the Capital and...
5. ### How to account for the subjects who are no more available for recording observations over time?

Hello, I have taken a simple random sample in January, which is 10% of the population. Every month there is 10% people leaving the population, which will make my sample size also shrink. Over the time, there will a time where I will not have any subject left in my sample to record the...
6. ### Several test groups and one big control group: split the group or not?

Dear members I'm preparing a test of proportions regarding a campaign redemption of several groups which have all common "demographics" but have been stimulated into different ways. At the same time I have a big group of people with the same demographics but which have not been stimulated...
7. ### Sample size calculation for cross-sectional survey (2 Time points)

I am working on a study design for a study to determine behaviors and structural barriers to health seeking at baseline for HIV negative young women 15-19 years, conduct interventions for 2 years and later study their behavioral changes and remaining structural barriers after intervention. This...
8. ### One population, two sampling methods, how many logistic regression models?

Can I include an explanatory variable that stratified the population in model? I have 400 randomly selected urban households. I have 400 rural households selected from 15 villages census style. Food insecurity (dichotomous) is my outcome variable. I want to find determinants of household food...
9. ### Sampling methods, which is more appropriate?

I have been collecting data on the temperature in an experiment for the last couple months, and I'm interested in the rate of temperate changes. The total amount of data is extremely large, and takes a long time to process, even using multi-threaded code. Currently I'm doing option 1, but I'm...
10. ### Sample design problem

A healthcare provider has been paid on N claims for certain health services, some of which may have been unauthorized. I must draw a sample of n claims to estimate the total payments to this provider for unauthorized claims: Y = Sum of I(k) * X(k) for k = 1 to N where: I(k) = 0 if claim k is...
11. ### How many measurements needed to distingish between two outcomes?

I have a historical dataset of about 500 measurements. Datapoints that turned out to indicate A or B, each have a distribution from which I computed mean and std. If I plot a histogram of these measurements, I have two semi-overlapping gaussian distributions. Those measurements that indicated A...
12. ### Partitioning Longer Survey

I have to field a necessarily long marketing survey. I think that there are techniques for partitioning the questions so that all are covered in the aggregate, but no one respondent sees or answers them all. 1. Is there a term of art for doing this? I've fumbled around in search engines to...
13. ### Advice on sample frame and sample size

I'm involved in a 4-yearwater supply, sanitation & hygiene project for mainly pastoralist (nomadic)communities in northern Kenya. We need to conduct a baseline survey for anumber of indicators against which the project will be later measured. As anon-statistician I'm struggling with applying...
14. ### Increasing sample size with a second sample?

This is not a homework question but I think it is an elementary question: Say I have a simple random sample (without replacement) of 50 items from 500. Now I decided I want to increase my sample size to 60 items. I know that I can use my original seed number to generate a sample of 60 where...