A sample is any part of the fully defined population. A syringe full of blood drawn from the vein of a patient is a sample of all the blood in the patient's circulation at the moment. Similarly, 100 patients of schizophrenia in a clinical study is a sample of the population of schizophrenics, provided the sample is properly chosen and the inclusion and exclusion criteria are well defined. In many surveys, studies may be carried out on large populations which may be geographically quite dispersed. To obtain the required number of subjects for the study by a simple random sample method will require large costs and will be cumbersome. In such cases, clusters may be identified (e.g. households) and random samples of clusters will be included in the study; then, every member of the cluster will also be part of the study. This introduces two types of variations in the data – between clusters and within clusters – and this will have to be taken into account when analyzing data. The focus of this book is on the 'why' of performing statistical calculations so that the 'how' of those same calculations makes sense.

Statistics without tears: Populations and samples - PMC Statistics without tears: Populations and samples - PMC

Rowntree wants you to understand the concepts instead of the formulas, so it makes the read easier. If you ever had to do null-hypothesis testing in school decades ago, the content should come easy to you. An easy and useful read on the subject of Statistics. This is a book for the layman that (by its own definition) does not go into the mathematical equations as "there are enough books on that". What it does, however, is to introduce and explain the concepts in a way that can be easily digested. My one complaint would be that there are some errors in the few equations that it does use. The study population is the subset of the target population available for study (e.g. schizophrenics in the researcher's town). Rowntree says at the end If you feel I've raised more questions in your mind than I've answered, I shan't be surprised or apologetic. The library shelves groan with the weight of books in which you'll find answers to such questions (p185), although having said that to my eyes this is pretty comprehensive for a non-technical reader and the kinds of questions it has raised are not ones I require answers to. The book is clear and plainly explained with worked examples it is written in a seminar style - so the flow is interrupted by mini-questions. I was interested by one example which set out how by doing a single tailed analysis in a drugs trial you can potentially skew the presentation of the result to make a drug appear far more effective than it is ( Lies, damned lies and statistics afterall) A sample may be defined as random if every individual in the population being sampled has an equal likelihood of being included. Random sampling is the basis of all good sampling techniques and disallows any method of selection based on volunteering or the choice of groups of people known to be cooperative.[ 3]A brief and informative read that helped me review the statistics material I had studied, but I need to qualify that by saying this will not be enough. It's a good starting point, and if you've studied statistics before then it will remind you of the terms and help you conceptually. However, you will need to supplement this with other reading and practice centred around why you want to understand statistics and the tools you want to use.

Statistics without Tears! - BOPA Statistics without Tears! - BOPA

Catchment areas depend on the demography of the area and the accessibility of the health center or hospital. Accessibility has three dimensions – physical, economic and social.[ 2] Physical accessibility is the time required to travel to the health center or medical facility. It depends on the topography of the area (e.g. hill and tribal areas with poor roads have problems of physical accessibility). Economic accessibility is the paying capacity of the people for services. Poverty may limit health seeking behavior if the person cannot afford the bus fare to the health center even if the health services may be free of charge. It may also involve absence from work which, for daily wage earners, is a major economic disincentive. Social factors such as caste, culture, language, etc. may adversely affect accessibility to health facility if the treating physician is not conversant with the local language and customs. In such situations, the patient may feel more comfortable with traditional healers. As someone that has previously studied many of the covered topics, this was a comfortable way of reviewing and organising the subject matter. I found that some of the explanations provided were far more accessible than the way in which I was first taught statistics.

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Aside from the mathematical complexities, I was plagued by programming languages that seem to have been designed by dinosaurs (I’m looking at you, “R”) and interaction with material that I thought I would have no relationship with following my graduation. This article has been cited by the following publications. This list is generated based on data provided by Clinical and demographic characteristics define the target population, the large set of people in the world to which the results of the study will be generalized (e.g. all schizophrenics). This book was probably the most lucidly written book that I have come across that explains Statistics to a person entirely alien to the field.