Use sampling data to recommend a section for digitalization in the CCAC library
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Inference through sampling

wb_incandescentIntroduction

Sampling allows us to make inference about a parameter such as the mean that describes a larger population. The mini-projects in this section will invite you to experimentally explore the relationship between sample statistics and population parameters.

bookSampling learning resources

The following resources will anchor our project academically:

1. Lock^5 Textbook:

The following sections of our official textbook, the Lock family's Statistics: Unlocking the Power of Data, treat sampling, and inference using confidence intervals and P-values

2. The Locks family on tape: Intuitive approach to confidence intervals

3. Statistics on Libre Office by Dana Lee Ling

This excellent free online book is built on open source Libre Calc and contains compact presentations of core statistics concepts.

Normal distributions and sampling

stats with calc

bookCore Concept A: Population versus samples

evaluation spectrum

bookCore Concept B: Confidence intervals

evaluation spectrum

Mini-project 1: Interpreting confidence intervals

Mini-project 2: library book sampling

The directions to this exercise are fully contained in the LINKED documents on this page--which all live in our data/docs root, available as an editable or a printer-friendly file. Be sure to consult our course textbook, the Lock5, and Lock5.com/StatKey

Analysis Guide Editable

Analysis Guide PDF

Shared drive for library upload

Library of congress classification scheme

Spring 2019 Results

library book sampling data library book sampling data library book sampling data library book sampling data
Section ND: Painting versus NB: Sculpture
library book sampling data library book sampling data library book sampling data library book sampling data

Mini-project 3

bookAnalysis Steps

Step 1: Load variable data into statkey

The 95% confidence interval is (290,395) around our point estimate of 339 pages. Width of 105 pages.We believe that if we repeatedly sampled 35 books from the JK section, we would expect about 95 out of 100 of these samples to "capture" or include the true population parameter i.e. the actual average number of pages of all books with a LCCN prefix of JK.

If I'm willing to accept a lower confidence, of 80%, my interval is only (306, 374), with a width of 68 pages. We would expect 80 out of 100 repetitions of this sample to include the true population value.

Unfortunately we cannot know given our current experimental structure if our single sample does in fact capture the true mean.

The central tradeoff we face:

If we wish to speak about the population mean with more PRECISION (smaller confidence interval) we must accept a LOWER CONFIDENCE rate (i.e. we would expect fewer samples, if repeated, to capture the true population value)

evaluation spectrum
Use the statkey confidence interval generating tool for conducting your analysis