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

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3
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1answer
18 views

Bootstrap for small sample

Does bootstrap method help for small sample? In my mind, bootstrap is a solution when you don't have belief in a normality assumption. If your data is random enough, it might be convincing to sample ...
1
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0answers
17 views

Sampling size question [closed]

I wanted to know the sampling size of a population where size is low and moreover it doesn't follow a normal curve. Moreover I wanted to roll out quality numbers at monthly level as the weekly level ...
0
votes
1answer
30 views

Can I run generalized linear mixed models using lme4 on very small sample sizes?

I am analyzing data (size/survival) of two groups of fish (Group1, Group2) mixed together in tanks with two different environmental variables applied at two levels to the tanks, e.g. ...
0
votes
0answers
9 views

How to ensure sample independence across iterations when using the EM algorithm?

I have a problem which uses the EM algorithm. For my purpose, I would like to run it such that the samples used in the $t$ iteration are independent from those used in the $t+1$ iteration. One way to ...
0
votes
1answer
16 views

Intrarater reliability test for a single subject?

I have repeatedly measured the volume of the brain of 1 subject in an MRI study. Measurements were acquired by the same rater (myself) on three separate occasions resulting in three measurements of ...
0
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0answers
24 views

Minimum sample size at the last stage of multistage sampling

We're conducting a two-stage survey. First stage is schools, second stage is students. What is the minimum number of students per school that we need to sample? I remember reading that the minimum ...
0
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0answers
15 views

Normality and homogeneity test for small sample size

I would like to inquire if testing for normality and homogeneity is still necessary for my data from an experimental where trials were done only three times. Or can I directly perform ANOVA and ...
4
votes
1answer
73 views

Adjusting for variance-sample size dependence

In many survey results that are released to the public with respect to ranking (whether it be school ranking, city crime rates, etc.), one of the many criticisms of these is that some which have small ...
0
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0answers
19 views
0
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0answers
12 views

How do I evaluate the impact of sample bias on the generalizability of my findings?

I am performing a regression analysis to identify predictors for my DV, using survey data. When comparing auxiliary information on my participants (in my case firm size and industry) to the available ...
0
votes
0answers
18 views

Weighting method for small sample size

When I try to apply RIM weighting to correct the selection bias in my survey data, some weights become very small, as the bias is quite substantial. Also, my sample size is relatively small. As a ...
0
votes
0answers
19 views

non-normal one sample t test N = 19

I have sample data that appears to be right skewed and the Shapiro-Wilk test in R returned: W = 0.83092, p-value = 0.003334. I need to test the confidence that the population mean is different from ...
1
vote
1answer
25 views

Estimating a “true” value with a noisy number of additive noises

I want to recover an estimate of the "true" value of a variable from a small set of noisy observations (5–20). I have an a priori model describing the physical process that generates the ...
0
votes
0answers
10 views

Help me inform multiple regression coefficients with additional dataset

I have a data set with 24 year on year observations. That is for a single company. I have around 500 companies with incomplete datasets (i.e. with missing values). I am trying to predict a Y ...
0
votes
0answers
19 views

Multiple hypothesis correction - small n, large p?

I have some biological data (expensive), with only 3 replicates/"samples", measuring methylation level of 450,000+ loci. I am doing hypothesis testing comparing 3 samples of one group to 3 samples of ...
1
vote
1answer
45 views

Calculate a slope with only 3 points?

I have a dataset that includes repeated counts of individuals at 3 successive time points. I have 8 experimental groups, with 5 replicates each (count repeated over 5 days). My goal is to obtain the ...
0
votes
2answers
72 views

Minimum number of observations needed for penalized regression?

I'm wondering what should be the minimum sample size to perform ridge, lasso or elastic net regression. I have a binomial outcome that I want to relate with a set of features (18 features in some ...
0
votes
0answers
24 views

repeated measures analysis for small sample size

I have an intervention study with a very small sample size and am trying to decide the best way to analyze it. Any suggestions would be extremely helpful. Here is some more information: Measurements ...
1
vote
0answers
23 views

Panel data with small N. Is it ok to use “lme”?

I have longitudinal observations from 6 individuals. For each individual, there are 29 time points when data have been collected. Can I use "lme" in R to estimate a model? Should I check for ...
0
votes
0answers
13 views

Can I use growth curve modeling with N=6 and 29 time points?

I have data of six children tracked for 29 time points. I am interested in the change of some measurements over time. I would like to know how children differ from each other. Do you think I can use ...
1
vote
0answers
27 views

Modeling bias in reviews of conference papers

An article in Science Magazine claims that A little bias in peer review scores can translate into big money, simulation finds . The paper referred to there is paywalled, though. Can anyone point me to ...
2
votes
0answers
24 views

Quasi-experiment: sample size & statistics

I am conducting a quasi-experimental research in a school, where I have access to 100 students who are chosen as classrooms and who will be the participants of the study. I am interested in the ...
2
votes
1answer
55 views

One-sample test, small sample size (n=3), non-normal data

I have approximately 5,000 variables, each with 3 data points. These numbers are ratios, i.e. bounded at 0 and generally non-normal. I'm interested in testing whether the mean of each of the 5,000 ...
0
votes
0answers
35 views

What if no Model fits and no non-parametric alternative exists?

I'm doing analysis on data from an ecological field study. I have fields (n=12) of different age. I treat age as a factor (age class) having 4 levels (1,3,5,and 7/8 years old). Hence the number of ...
1
vote
0answers
19 views

Test for difference between small number of Gaussian-like time series

I'm looking to test for a difference between populations A and B. Each population is made of three time series which can be modeled well with a Gaussian or Gaussian mixture, and each have 55 data ...
0
votes
0answers
8 views

Small sample sizes for some categories, not for others and ranking them?

[nb: I have zero stats/probability/etc background, but write code; apologies] I'm playing around with some game data - for example, a player has with each ship: 232 wins, 219 losses as "Apocalypse" ...
5
votes
1answer
59 views

Correction for multiple testing on a modest number of tests (10-20) with FDR?

False Discovery Rate (Benjamini-Hochberg) is typically used on 'Big Data', such as genetic studies using 100s of tests. But can it also be used on smaller numbers of tests? For example, looking at the ...
2
votes
0answers
25 views

Sample size for large population with rare events?

I want to calculate what fraction of the US population, say 300M, responded to a commercial shown on TV based on a small sampling of data. I think only about 100,000 will respond, 0.0003% How ...
0
votes
1answer
48 views

Performance of a classifier change heavily

I'm using a data set of 32 face persons and a svm-rbf to classify and a random group of 70% for train and 30% for test. The problem is that my results are heavily dependent of the random group used ...
1
vote
0answers
26 views

Residential Real Estate Appraisal

Appraisers use adjustments to derive the value of a subject property. For example, if a similar house has 100 more square feet of living space, and sold for $210,000, we deduct the value of the space ...
12
votes
4answers
666 views

Graphing small samples

I have a small data set of 14 separate times to complete a task. However I am having difficulty finding an appropriate graph to use to graph the data. If the sample was larger I would use a box plot ...
0
votes
0answers
8 views

How to handle with a very small sample and unbalanced dataset? Is GLMM a good option?

I'm having some troubles in analyzing and make the most of my dataset. My hypothesis: pharmacological condition maximizes utility of the decision regardless of the context (by providing the necessary ...
0
votes
0answers
13 views

How to handle with unbalanced and small sample dataset? Is GLMM a good option?

I'm having troubles in analyzing and make the most of my dataset. My hypothesis: pharmacological condition maximizes utility of the decision regardless of the context (by providing the necessary ...
5
votes
1answer
80 views

Aging data in the German tank problem

The German tank problem is about estimating the total size of a set of objects from random samples of serial numbers. It can simply be done by: $$N \approx m+\frac{m}{k}-1$$ Where $m$ is the ...
0
votes
0answers
17 views

Combining Training and Validation Sets before passing model to Test Set

I have a situation in which I am building a model to predict a physical parameter of aircrafts, let's say it's parameter Y, Given several other measured parameters of aircrafts, let's call those ...
0
votes
1answer
78 views

How much sense does median of one number make?

Median of one number = the number itself. I am calculating the median price sq ft of properties of different areas based on the different data entries I have got that include their ID, area and ...
2
votes
0answers
33 views

Runs test for a very small sample

I have six measurements taken at different time-points in an experiment, and I want to show if these measurements have a dependence on time (i.e. are they random or not). I originally presented the ...
1
vote
1answer
51 views

G test with small observed counts (~zero)

I have an experiments that counts how many events happened during a certain period of time. The experiments is repeated many times in different "runs" (I have 65 runs). Here for example the list of ...
0
votes
0answers
13 views

Minimum sample size to establish a cutoff point

I conducted a case-control study (obese and normal body weight). I want to conduct ROC curve between my variables to establish a cutoff point for vitamin depending on insulin resistance risk. Does it ...
3
votes
0answers
63 views

Is Random Forest suitable for very small data sets?

I have data set comprising 24 rows of monthly data. The features are GDP, airport arrivals, month, and a few others. The dependent variable is number of visitors to a popular tourism destination. ...
0
votes
0answers
45 views

How to compare means of two sets when one set is a subset of another and the sample sizes are not

I have two samples containing citation counts for some publications. Of those samples one is a subset of the another. That is, subset contains some exact citation counts appearing on the other sample. ...
0
votes
0answers
26 views

Which t-test to use when different sized but dependent values are in question?

I have two sets of data. At the one hand manually known correct numbers for some index values such as: ...
0
votes
0answers
24 views

Using t-test when one of the groups is only two cases?

I apply ttest2 function in MATLAB for the following data sets: x = 21 5 6 5 2 5 2 13 28 2 y= 2 5 For this comparison whether means of those sets are equal MATLAB ...
4
votes
1answer
66 views

Calculate confidence levels of a stratified sample with missing units

I'm conducting a stratified survey among health institutions; 700 units were allocated into one of the 30 strata designed to reflect the proportionality of the population. However, it's been difficult ...
1
vote
0answers
20 views

help me choose statistical analysis for my undergrad thesis [closed]

firstly, i'm sorry if i'm not very good in statistics, i just need to finish my undergraduate thesis, but my professor is very busy, that he always don't have time for me to consult my research. so ...
1
vote
2answers
113 views

How can I assess many explanatory variables with a sample small enough for in-depth qualitative (case-study) analysis?

The problem: My study is on the impact of human factor on regional development. My “subjects” are regions of the European Union. 276 exist in total under NUTS 2 classification. The idea is to use a ...
2
votes
1answer
83 views

Cross-validation on really small datasets

Let's say I have a small dataset: data <- replicate(4,rnorm(13)) I want to test the out-of-sample predictions of a regression model as a function of ...
1
vote
0answers
32 views

Test for a difference of slopes

This seems like a basic question, and I feel kind of dumb that the answer is not obvious to me. The data look like this: Four count variables, all subtypes of a class of event--car crashes (A, B, C, ...
3
votes
1answer
68 views

Find best model to predict small dataset

This is my first prediction task. I have a (very) small dataset with 59 rows and 3 features. I hope that this are not way too little samples. ...
1
vote
2answers
41 views

How to apply Wilcoxon test to small sample with NAs?

I have the following data which show some values before and after a drug. I want to test whether the drug increased the mean. I think I should use Wilcoxon test, but I don't know what to do with ...