Refers to any statistical complication or problem due to having few data.

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1
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1answer
44 views

How to model a skewed Student's t disribution

I have a small number of samples (5) of a large population (~10,000). The samples are percentages and hence I know from the context that no answers are possible below 0% or above 100%. From this one ...
2
votes
0answers
16 views

How can I tell if I my sample size is large enough for reliable feature selection using LASSO regression?

I have a gene expression dataset with 20 samples, and am not going to be getting any more. There are ~28,000 genes and four clinical covariates associated with each sample. The gene expression values ...
1
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0answers
14 views

repeated measures design between subjects with non normal and small N

I’m examining the effects of a parent-delivered reading intervention on 11 child outcome variables at 3 different time points (pre, post-intervention and follow-up) with a control group. Total sample ...
2
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0answers
52 views

Big Data? Have we solved Small Data yet? [closed]

There has been a lot of attention on Big Data recently, where the problems are often more logistical (how to deal with large volumes of data) rather than statistical. At the other end of the spectrum ...
1
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1answer
24 views

How to expand sample subset with similar data

I would like to categorize a large sample and make some estimates for each category aka subset. The problem is that some subsets contain very few data points. How do I deal with that? For example: ...
1
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0answers
62 views

Why are small sample sized avoided in meta-analyses?

In most meta-analyses that I've read, the authors choose to exclude studies with really small sample sizes (e.g n=10). Why is that? Speculation I could speculate that one reason is that since the ...
1
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1answer
48 views

Suggest models for prediction based on small sample data

I am not a traditional statistics guy. I am from an electrical engineering background. So, spare me for lack of jargon. The model is to be used for predicting agricultural output based on previous ...
2
votes
2answers
40 views

Comparing different conditions on a binomial distribution

I have some data where I have tested a binomial random variable under 4 conditions. The null hypothesis is that they all have equal means, alternative hypothesis is that one or more means differ from ...
2
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1answer
35 views

What test of significance is best suited to compare concentrations, with only one sample of each population?

I have two large reservoirs of water with unknown concentrations of bacteria. I have only one sample of each reservoir: Sample of reservoir A: volume of the sample $=V_1$, number of bacteria in the ...
1
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1answer
29 views

(very basic) One-sample test for binary data

I've repeatedly measured a continuous variable and each measure has been assigned a populational percentile range it falls into (percentile ranges were estimated for general population in another ...
4
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3answers
210 views

Regression for really small data with high degree of multicollinearity and outliers

I'm working on a promotional response analysis. I have a really small real world dataset with 25 observations and 15 variables. The variables have a high degree of multicollinearity and some have ...
0
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1answer
51 views

Testing difference between two means. Skewed ( N1=21) vs Symmetric bell (N2=47). Wilcoxon rank sum test appropriate?

I need to test to compare the means of two samples, one with size 21 and the other with size 47. Histograms show Sample 1 is skewed to the right while Sample 2 has a bell symmetrical shape. ...
0
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0answers
39 views

Chi-square / Fisher test variable independence for an individual

I have a data set of $\approx$100 individuals showing pulse rate before exercise, pulse rate after exercise, sex, smoker status, weight etc. for each individual. I've been asked to select an ...
3
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0answers
140 views

Mixed ANOVA: small and unbalanced samples

I have to analyze two samples ($n_1=10, n_2=18$) in a design in which there is a between-subject factor (Groups: 2 levels) and a within-subjects factor (...
1
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0answers
51 views

Alternatives to a train-test split with a small data set

Let's say I have a small data set (~50 observations) and 50 or so explanatory variables, and I want to develop a linear model for the sake of prediction. First, I want to construct a correlation ...
0
votes
1answer
47 views

Panel data regression specifications

I am currently working with a panel data in which I have 6 countries, and the analysis is for 10 years. That is $n=6$ and $t=10$. Is it a good panel? I am really getting confused as people question ...
0
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0answers
29 views

literature on small samples and parametric survival models

I have an abundance of small data sets with right-censored data. There are different groups in each data set and I'd like to get confidence intervals for the regression parameters. Each data set has ...
0
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0answers
39 views

Sample size for SEM. What are the alternatives

I have 3 latent variables with 3 measures each. I understand the conventional sample size would be 15 participants per measure (i.e. 9 x 15 = 135). I have 85 participants and don't think I will have ...
5
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4answers
1k views

Warning in R - Chi-squared approximation may be incorrect

I have data showing fire fighter entrance exam results. I am testing the hypothesis that exam results are dependent on ethnicity. To test this, I ran a Pearson chi-square test in R. The results show ...
3
votes
1answer
180 views

How to choose train/test sample ratio, for machine learning?

I am building a real time machine learning module, which is not based on a huge** sample size, with hyper parameter grid search and cross validation process. I am looking for any insight/advice, as ...
0
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0answers
33 views

Sample size for binary text classification

In my application as a Binary text classification, one class has around 36,000 sample and another one has around 300 samples. I under-sample the first class. So, each class will have ~ 300 samples. ...
3
votes
0answers
103 views

Bootstrapping fits to a small sample

I have a sample of experimentally measured survival times that are quite noisy and vary stochastically. The survival probability of these events (number of events with a survival time of t or more) is ...
0
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0answers
18 views

Applying the distribution of a large sample to estimate probability for a smaller sample

I have the sample size, mean and standard deviation for the number of births per year for my county, but I'd like to transfer that information to a smaller population within the county (ie. a school ...
0
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0answers
48 views

CLT in a Monte Carlo simulation, small sample

A CLT says that asymptotically the sampling distribution of the sampling mean converges to the Normal. I would like to run a Monte Carlo simulation using information on one of the model's variables ...
1
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3answers
101 views

Distribution of a sample from a normal population

If I were to collect ONE sample of size 20 from a normal population, how justified would I be in claiming that the sample is normally distributed? I'm getting a little confused since by the Central ...
0
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0answers
123 views

data mining/predictive modelling methods for small data sets

I have a small timeseries dataset that has 30 records with 6 predictor variable and 1 response variable. I would like to regress my time series response with 6 predictor variables. I have been using ...
2
votes
2answers
88 views

Bernoulli Confidence Intervals for p very close to 0

Let's say I have the following observations from many Bernoulli distributions with different p (p1, p2, ..): Observations from Distribution 1: 10 successes, 100,000 trials, p_hat = 0.0001 ...
1
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3answers
657 views

Comparing means with unequal variance and very different sample sizes

I am trying to compare the means of the same variable between men and women. This is the statistics: ...
1
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1answer
57 views

ANOVA with very uneven sample sizes— Can fit be improved through reference to a more complete dataset?

I am analyzing a set of costs for contractor services for a particular city. These data have been extremely difficult to collect due the difficulty of contacting contractors and reluctance of ...
9
votes
2answers
276 views

Is randomization reliable with small samples?

Jerome Cornfield has written: One of the finest fruits of the Fisherian revolution was the idea of randomization, and statisticians who agree on few other things have at least agreed on this. ...
1
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1answer
57 views

How to estimate errors on a sample with very few data points

I have a very simple question to ask, but I can't figure this on my own. I have two samples: sample A with only three data points, and sample B with hundreds of points. For each sample I measure the ...
2
votes
1answer
33 views

Calculate $t$ value for expanded sample using just $t$ and $n$

Imagine a sample of observations $x_1 \dots x_n$ for which a $t$-value (i.e. $\bar x/SEM$) is known. Say an additional observation of zero is added to the sample so that we have $x_1 \dots x_{n+1}$ ...
2
votes
2answers
96 views

Fraction confidence intervals for small sample size

What is 95% confidence interval for the fraction of 5 successes out of 12 trials? Is it possible to compute confidence intervals for a sample of this size?
3
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0answers
101 views

Path analysis, sample sizes, and alternative analysis

I am examining how English ivy affects the occurrence of a salamander species under cover objects (e.g., logs). Soil moisture is assumed to be the major factor that affect their occurrence. My ...
2
votes
1answer
108 views

Creating alert system based on standard deviation and mean: How to deal with small sample size, trends and seasonality?

I'm trying to build a daily alert system to let me know when something unusual has happened in my analytics data that might require further investigation. Right now I'm taking 7 weeks worth of data, ...
0
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0answers
15 views

Sample Balancing

Trying to figure out a way to balance small samples. Comparing ratios received from a survey, but sometimes I will have 25 survey responses and sometimes I will have 1. The ratios I look at might be ...
1
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0answers
51 views

Confidence interval for a coefficient with small N

I have a question about the confidence interval of the estimator in a multiple linear regression. Here below you can find my model: ...
1
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1answer
126 views

Can this be modeled by a two-sample t-test?

Here is the question: A claim is made that men from two income families earn less than men who are the sole income earners in their household: To support this claim, data from a random sample of 22 ...
3
votes
1answer
115 views

When am I allowed to make linear regression on a small sample?

I'm trying to evaluate the linear correlation between to continuous variables (% value calculated from EEG datas and the area of an anatomical region of the brain). I have a sample of 18 right now. ...
0
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0answers
65 views

Best test for prediction in small sample

In the context a social sciences study, I’ve been limited to a small sample size and seek expert advice on the appropriate statistical approach to take. I’d like to go beyond the simplicity of ...
2
votes
2answers
197 views

Which test for small sample sizes?

I have got a total sample size of 12 soil samples which are splitted into 4 groups of $n=3$. A number of different variables were measured like content of organic carbon e.g. These data are ...
6
votes
1answer
254 views

What can be concluded from small sample size?

I had just conducted a test where the customer wants to see a 20% improvement in perforation length from a baseline perforator. The baseline perforator has not been tested in the customer's specific ...
2
votes
0answers
79 views

Robust estimation of mean with small sample size

Working with a 2D sensor. A row consists of 4096 samples, of which there are 16 reference samples (the rest are active). The reference samples do not measure the signal, but are used to estimate the ...
1
vote
1answer
175 views

How to analyse a Likert-type scale with a very small sample size (n=15)?

Data description: I have data from questionnaire data on 15 participants (small sample). Parents rated the frequency that they rough and tumble with their child: (1) Never, (2) not very often, (3) ...
0
votes
0answers
71 views

Small sample size (N=14) with data points measured at 6 different times

I have a study with 14 participants who received testing on Variable 1 at 2 different times (before and after the semester) to determine whether there is any change on Variable 1. Each participant ...
0
votes
0answers
109 views

Alternative to factorial logistic regression for small-n experiment.

I need help figuring out an appropriate statistical test for the following small scale experiment: 2x2 design (Treatment-Adult; Treatment-Child; Control-Adult; Control-Child) DV: binomial ...
0
votes
1answer
104 views

Unequal sample size t-test, but with group-effect

I am researching how people watch video lectures together. I have two conditions as follows: (1) 3 groups of 4 learners watch one video lecture on a shared display, but there is only one control (to ...
1
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1answer
82 views

Significance of correlation with only 11 datapoints

I am currently working on my thesis and calculating some simple correlation coefficients. I only have 11 datapoints available, but I would like to assess the statistial significance of my results. The ...
2
votes
2answers
72 views

Statistics for small and unequal samples

I have a pre-test, post-test, non-equivalent groups experiment, with a sample of 62 (control and experimental groups have 31 each). My objective is to compare the effectiveness of a model of teaching ...
2
votes
1answer
507 views

ICC and Kappa totally disagree

Much has been written on the ICC and Kappa, but there seems to be disagreement on the best measures to consider. My purpose is to identify some measure which shows whether there was agreement between ...