# Questions tagged [sample-size]

This tag is ambiguous. Use it when the question is about sample size and NONE of the following are more appropriate: [small-sample], [large-data], [statistical-power], [underdetermined], or [unbalanced-classes].

1,842 questions
Filter by
Sorted by
Tagged with
8 views

### Sample size calculation in two different population for administration of a questionnaire

I need some help calculating a sample size. I have two groups of people to whom I need to fill out a questionnaire. Group A consists of 45,000 people and group B consists of 3,000 people. How do I ...
20 views

### Adequate sample size for non-normal population

There are 197,058 record holders (population) with an average of K shares each. I don’t know K, and the sample collected so far of ~24,000 observations appear to be non-normal (inverse gauss). I’m ...
15 views

### Calculating Sample Size from Prediction Equation (multifactorial linear regression)

I am conducting a study that seeks to assess differences in fat distribution in transgender women, as compared to cisgender men and women. A prior study has previously published separate formulas ...
1 vote
45 views

### Sample population for AI Study

I have a study. I have 150 AI-generated images and 150 human-generated images. I have created a survey where respondents are given 10 images randomized from these 300 images. For each picture, they ...
19 views

### What does "roughly equal sample sizes" mean? [closed]

"Roughly equal" is ambiguous. My professor told me to use the cut off ratio of 1.5 to determine if my two sample sizes are roughly equal (i.e., n1 divided by n2) but I cannot find the ...
1 vote
34 views

### How to do a power analysis for a virtual species distrubition model which uses random forests

I am creating virtual species distributions on a 100x100 grid (for now). Each layer of the grid represents one environmental variable. The "suitability function" defines the probability of a ...
39 views
+50

### Compare CCDF of datasets with different sample size

I have 3 dataframes with the same structure (each dataframe includes a different type of tweet). Here are the columns of dataframes: id, ...
7 views

### Sample size - Diagnostic Accuracy Study

We have a gold standard test and a new test, and want to compare them prospectively, in a diagnostic accuracy study. I want to work out the sample size required. I have done some reading, and there is ...
29 views

### Calculating sample size when you have 2 treatments and uneven distribution

I have 2 new conversion webpages to test. Leadership recommends 80% traffic to existing conversion webpage and 10% each to the 2 new conversion webpages (non-negotiable) How do I calculate sample size?...
1 vote
30 views

14 views

### What should be the significance test when population size is unknown(know that it's more than 1M) and sample size is greater than 30?

I have a dataset with around 1M data. But, in real-life it should be more. From the dataset after first step processing for specific task, I got 50K data. Then I processed it again for a specific ...
15 views

### Assessing the Validity of Conclusions Based on Limited Findings

Introduction: Archaeological research often involves drawing conclusions about past societies and cultures based on a limited number of artifacts or findings. In some cases, such as the study of ...
1 vote
119 views

### Statistical power and sample size for Poisson regression: specifying the "mean exposure"?

I am trying to perform an apriori power analysis to estimate sample size for a Poisson regression model. The background is that a RCT is proposed to compare the rate of pill consumption between two ...
1 vote
20 views

### What is the sample size calculation for a discrete outcome (count variable)?

What is the sample size calculation for a discrete outcome (count variable)? For example, I want to design a trial with a placebo and a treatment. The outcome is the number of days of treatment : 14 ...
48 views

### Linear model with different sample size

I have a continuous dependent variable and one categorical independent variable (with three levels). For the three levels, I have 42, 33, and 45 observations respectively. So, in short, I have unequal ...
19 views

### Is a response rate of a population considered the sample?

Let's say my survey population size is 1000 and I send a survey to all 1000. And only 200 responded. Is the 200 considered my sample size? If yes, can I calculate a margin of error on the questions in ...
29 views

### Sample size calculation cf. Alonzo et al

I would like to use a sample size method proposed by Alonzo et al.* More specifically, I would like to use their sample size method for matched screen-positive studies (section 6 in the paper). I have ...
8 views

### Comparing two binomials with with partially matched sample

Imagine a scenario where I want to understand a population's support for a political candidate. I sample n=500 people randomly with replacement and ask them if they want to vote for candidate A or B. ...
1 vote
13 views

### Are there special sample size calculations involved for the analysis of residuals in a contingency table?

This is a purely theoretical question (for the moment at least), so not a lot of details to share. If I plan an analysis of residuals following a chi-squared test of independence, I was wondering if I ...
1 vote
20 views

### Is there a statistical approach to determine the minimum sample size for comparison of sums over time?

I have the number of items sold of various products over time from a supermarket. Each product belongs to a category of products. Some categories have a large number of items sold and some categories ...
27 views

### Split Sample for EFA and CFA with Smaller Dataset

I have a dataset (n=290) that I need to run an EFA. I was hoping to also run a CFA but I'm unsure if I have enough data to do a split sample approach. Please advise.
1 vote
35 views

### Sample size and power analysis: Chi-square

Can someone help with a sample size analysis question? Study design: I have a sample randomly assigned to answer 1 of 5 different questions that vary in difficulty (1 - Easy -> 5 - Hard). The ...
51 views

### A/B test - sample size calculation and unit of measurement

Does the unit of measurement change how we calculate sample size? For example, if we were to run an A/B test on ads with our target metric being click-through-rate, and we are doing a sample size ...