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8k views

How to check whether a sample is representative across two dimensions simultaneously?

I'm attempting to develop a standardized method to check whether one set of locations are representative of a larger set. In this particular case, I'm attempting to look specifically at their ...
10k views

SPSS: “Weight cases” by multiple factors, by taking the product of weights?

My understanding is that a sample can be adjusted based on a known population using the "Weight Cases" function in SPSS. What is the proper procedure for weighting by multiple factors? Let's say I ...
164 views

Representative resampling

I am working with a population in which each individual has, among others, 6 observed variables that can be 0 or 1: $X_i \sim Bernoulli(p_i),\ i=1,...,6$ . I know the "true" value for the ...
238 views

How to compare sampled areas to the Census?

I would like to discriminate sampled areas that are representative or not representative of their corresponding population, for a given characteristic. Suppose I have surveyed areas (i.e. Census ...
64 views

Is my data representative of Bristol?

I've got some data about people in Bristol. I have about 75,000 records. Part of my dataset is each respondants age. Aside from this, I have also downloaded census data for Bristol, which gives me ...
43 views

How to interpret if my sample statistic is way out in the tail of the bootstrap distribution

I use bootstrapping to generate the distribution / histogram of my sample statistic and find out that the value of my real sample statistic is way out in the tail. What does this mean? Does it mean ...
160 views

What is the number of subjects needed to be representative for a small, finite population?

I have been studying an organisation with 58 people with a number of Likert style questionnaires. The data are not random samples but rather incomplete census's. For the 6 questionnaires I managed to ...
22 views

Hand-picked items in the training set, good idea?

The training, validation and test sets for the classification problem I'm working on were randomly sampled from real data. Because of this, I am fairly confident that there are representative. I want ...
39 views

Instagram representative sample

I am doing a survey to study both sellers and consumers behaviour on Instagram in Kuwait. My question is how to decide on the sample size? What sampling design should I use since there is no sampling ...
198 views

Measuring representativeness of a (non-random) selection

I am looking for a numerical value that expresses how representative a (non-random in this case) sample from a population is regarding the distribution of a certain attribute. Take for example, the ...
564 views

Check if sample is representative of a larger sample

From a larger sample of tabular data, I have picked certain rows that meet a certain condition (this condition is unrelated to the actual data in the rows). Now, I want to know if the distribution of ...
448 views

Is my sample representative of the population I am trying to measure?

We have completed a survey of FTSE350 companies, but only received 49 responses. We assume that this response rate means that our results are not representative of the FTSE350 as a whole, but wanted ...
16 views

How to deal with a non representative sample [duplicate]

Say we want to know whether age can explain the probability of a particular response (which is binary 0 = negative and 1 = positive). Plotting the data and applying a logistic regression we get the ...
31 views

Sample Representing a Different Population

I have two sets of populations: containing 1.5 million and 5.5 million units. I need to select a sample out of 5.5 million population so that the sample represents the 1.5 million population based on ...
34 views

Data management of a representative sample

In our original database there are some variables which are quantitative, but actually they are categorical variables. Our question is, should categorization be done in the original database or ...
195 views

I study subpopulation so huge that chi-squares test insists it is not representative. How do I get confidence intervals for my population?

I want to get results about population A. But all I can study is subpopulation C of B, where B is a subpopulation of A (that is, C $\subset$ B $\subset$ A). Each member of A is classified into one of ...
33 views

How can I calculate when a text corpus is representative of a language?

I am collecting and analyzing articles and other publications for building a text corpus. I'd like to know how to calculate when my text corpus is representative of a field. That is, how many texts, ...
10 views

Blocking and representative samples

I am trying to measure the Net Promoter Score of a segment of customers for an online product. There is an attribute of these customers that I believe might affect their Net Promoter Score. So I want ...
6 views

Splitting an i.i.d. sample in two by criterion - what survives of independence and population representation?

Assume that I have available a $k$-dimensional i.i.d. sample of size $n$, collected in the $n \times k$ matrix $\mathbf X$. Each column represents a series of realizations from a random variable. ...
45 views

How to best represent a geographical area as point

I need to check a relationship(?) between land surface temperature (LST) and total population census tract (shapefile) wise where i am trying to relate social factors (e.g. total population, female ...
17 views

Find sample size representative of data

I have data from multiple farms, showing how many healthy and lame animals are found on each farm, and how many animals were there in total. I would like to calculate, statistically, how many animals ...