John Perry Barlow on politics and the internet (1998)minireference2021-12-29 | This is an excerpt from 16:14 until 17:44 from the video C-SPAN source video c-span.org/video/?110679-1/politics-government-digital-technologySec 3.2.3 Confidence intervals for the population meanminireference2023-08-16 | In this video we'll construct confidence intervals for the mean of an unknown population based on a sample taken from that population.
Notebook: nobsstats.com/notebooks/32_confidence_intervals.htmlSec 3.2.4 Confidence intervals for the population varianceminireference2023-08-16 | We construct confidence intervals for the population variance based on one sample of observations. We'll show constructions both on the chi-square distribution and bootstrap estimation.
Notebook: nobsstats.com/notebooks/32_confidence_intervals.html#confidence-interval-for-the-population-varianceChapter 3 Inferential statistics introminireference2023-03-29 | Chapter 3 is all about inferential statistics. Suppose you have collected the sample (x1,x2,...,xn) from a population. You assume the probability model X ~ ℳ(θ) describes the population, where ℳ describes the model family (e.g. uniform, Poisson, normal, exponential, etc.) and θ are the unknown model parameters that characterize the specific population you're interested in. Statistical inference is a bunch of tricks that allow you to use the observed data in the sample (x1,x2,...,xn) to compute an estimate θ̂ that approximates the unknown parameter θ.
The good news is, once you understand estimators, you'll know everything you need to know to understand statistics in a deep way. Once you learn the "math machinery" of estimators and their sampling distributions, all the rest of the chapter (confidence intervals and hypothesis testing) will be smooth sailing.
See nobsstats.com/notebooks/31_estimators.htmlSec 3.1.3 Sampling distributionsminireference2023-03-29 | The sampling distribution of the estimator g, is the distribution of estimates we might observe when we compute the estimator on random samples. This is the most complicated concept in this chapter, so in this video you'll see me try my best to use visuals, math, and code to explain it.
See nobsstats.com/notebooks/31_estimators.html#sampling-distributionsSec 3.1.4 Approximating sampling distributionsminireference2023-03-29 | In realistic statistical inference scenarios, the population parameters are unknown, so if we want to report the uncertainty in our estimates, we must learn find some way to approximate the sampling distributions from observed data (e.g. from a single sample).
This lesson introduces the bootstrap estimation procedure (a computational approach) and the analytical approximation methods (based on math formulas) for approximating sampling distributions.
nobsstats.com/notebooks/31_estimators.html#approximating-sampling-distributionSec 3.1.5 Sampling distribution of the meanminireference2023-03-29 | This lesson is a step-by-step introduction to the various methods for estimating the sampling distribution of the man. In particular, we'll show an analytical approximation based on Student's t-distribution (very good for small samples coming from a normally distributed population). We'll also show how to obtain an approximation to the sampling bootstrap of the mean using bootstrap estimation.
See nobsstats.com/notebooks/31_estimators.html#id2Sec 3.1.6 More sampling distributions: var, dmeans, Explanations and Discussionminireference2023-03-29 | Quick overview of the analytical approximations and bootstrap estimates for the sample variance and the difference between means. This video also includes a walkthrough of the Explanations and Discussion subsections.
Exercises notebook mybinder.org/v2/gh/minireference/noBSstatsnotebooks/HEAD?labpath=exercises%2Fexercises_31_estimtors.ipynb Try them! Remember, statistics is not a spectator sport!04 LINEAR MODELSminireference2021-11-22 | Linear models allow us to describe relationships between two continuous quantities x and y. We assume the output Y is distributed according to Y ~ b+m*x, in other words the x-Y relationship is a line of the form y=mx+b. In this video we study the case when each employee receives a variable amount of stats training (anywhere from 0 hours to 100 hours), and the ELV value is modelled by the relationship ELV ∼ 𝛽0+𝛽1*hours, where 𝛽0 is the intercept and 𝛽1 is the slope. The notebook shows several different ways to fit the model (find the best choice of parameters 𝛽0 and 𝛽1), interpret the results, and make predictions.
Notebook: mybinder.org/v2/gh/minireference/noBSstatsnotebooks/main?labpath=stats_overview%2F04_LINEAR_MODELS.ipynb03 STATS (part 5/5) - Confidence intervals for the effect sizeminireference2021-11-22 | In this video we'll learn how to provide rigorous estimates of gains in ELV for employees that complete the stats training, which is called effect size in statistics. We'll learn two different ways of estimating the effect size: one based on resampling methods (bootstrap) and another based on analytical approximations and Student's t-distribution. Both approaches give us a confidence interval, which describes the range of values for an effect size we can expect, and we can give a 90% guarantee on the procedure we use to generate the interval.
Notebook: mybinder.org/v2/gh/minireference/noBSstatsnotebooks/main?labpath=stats_overview%2F03_STATS.ipynb starting at "Estimating the effect size"03 STATS (part 4/5) - Hypothesis testing using the t-testminireference2021-11-22 | Analytical approximation methods in statistics provide ready-made formulas for describing the sampling distribution in various statistical analysis scenarios. These formulas are normally taught in STATS 101 courses because they require very few steps and can be applied without needing to understand the math models. For the specific scenario of comparison of two group means, we can use Student's t-test (so called because it is based on Student's t-distribution). This video shows how to apply Student's t test to obtain the p-value 0.047 and reject the null hypothesis.
Notebook: mybinder.org/v2/gh/minireference/noBSstatsnotebooks/main?labpath=stats_overview%2F03_STATS.ipynb starting at "Approach 2: Analytical approximations for hypothesis testing"03 STATS (part 3/5) - Hypothesis testing using the permutation testminireference2021-11-22 | The permutation test allows us to obtain the sampling distribution under the null hypothesis H0 by using existing sample data and a clever "shuffling" of the group labels. Using this trick, we obtain the sampling distribution of the difference between group means according to the probability model for H0. We then find where the observed difference between group means d=130 falls within the sampling distribution to obtain the p-value. Since the p-value we obtain is less than 0.05 our conclusion is to reject the null hypothesis, i.e., we conclude that there is a statistically significant difference between the groups means.
Notebook: mybinder.org/v2/gh/minireference/noBSstatsnotebooks/main?labpath=stats_overview%2F03_STATS.ipynb starting at "Approach 1: Permutation test for hypothesis testing"03 STATS (part 2/5) - Hypothesis testing introminireference2021-11-22 | Hypothesis testing is an approach to formulating research questions in the form of yes-or-no decisions. Hypothesis testing is a standardized procedure for doing statistical analysis, and a common tool use din academic research papers. We formulate research question as two competing hypotheses: - H0, the null hypothesis, which is a baseline, skeptical claim like "no difference" or "zero effect", and - HA, the alternative hypothesis, which usually embodies a theory or model that the researchers want to study.
In order to justify any study or analysis of the alternative hypothesis HA, scientific convention requires us to first "reject the null hypothesis," which we can do if we can show that the observed data is very unlikely (less than 5% chance) to have occurred by chance under H0. The logic is if the data is unlikely to occur under H0, this lends support to HA and further study is warranted. The alternative is that we "fail to reject the null hypothesis," which means the data observed is consistent with the "no difference" or "zero effect" data model, so does not require postulating any alternative hypothesis.
Notebook: mybinder.org/v2/gh/minireference/noBSstatsnotebooks/main?labpath=stats_overview%2F03_STATS.ipynb starting at "Hypothesis testing"03 STATS (part 1/5) - Intro and Estimatorsminireference2021-11-22 | Estimators (functions 𝑓 computed from samples) are a fundamental tool for statistics. The descriptive statistics we saw in the DATA chapter are examples of estimators: the sample mean is an estimator for the population mean, and the sample variance is an estimator for the population variance. We denote by 𝑓(𝐱) value of the estimator computed from a particular sample 𝐱. We denote 𝑓(𝐗) the value of the estimator computed from a random sample 𝐗, and refer to the probability density function of 𝑓(𝐗) as the sampling distribution of the estimator 𝑓.
This video provides a detailed hands-on discussion about the difference-between-group-means estimator `d = mean(xA) - mean(xB)`, which will is the math building block we'll need for both hypothesis testing and estimation. We'll obtain the sampling distribution for the difference-between-group-means estimator using both simulation and mathematical modelling techniques.
Notebook: mybinder.org/v2/gh/minireference/noBSstatsnotebooks/main?labpath=stats_overview%2F03_STATS.ipynb02 PROB - Probability theoryminireference2021-11-22 | This video introduces some fundamental topics from probability theory like random events, random variables, and probabilistic models. Understanding probability theory allows us to build mathematical models for the variability in data we observe, and we're lucky to have the lego pieces in `scipy.stats.distributions` docs.scipy.org/doc/scipy/reference/stats.html#probability-distributions at our disposal. Using the code from `scipy.stats.distributions` we can model most common random variables, generate random samples, do calculations using the probability functions and their inverses, etc.
The second half of the video is concerned with that probability distribution for samples of size n from a probability distribution. We study the properties of certain statistics (quantities computed from a sample) and learn about the Central Limit Theorem which tells us some useful facts about the distribution of the sample mean (usually denoted as overline-x) from any distribution.
Notebook: mybinder.org/v2/gh/minireference/noBSstatsnotebooks/main?labpath=stats_overview%2F02_PROB.ipynbIntroduction and 01 DATAminireference2021-11-21 | In this video, we'll introduce the running example we'll use for the whole video series: Amy's experiment about providing additional training to her startup employees. In the second part of the video, we'll illustrate concepts from chapter 01 DATA like extracting data from a spreadsheet, transforming data from "wide" to "tall" format, and viewing descriptive statistics like histograms, box plots, strip plots, and numerical summaries.
Linear algebra is the study of vectors and linear transformations. This video serves to introduce the computational, geometrical, and theoretical aspects of linear algebra.
Linear algebra is the study of "linear structure" in all its forms and shapes. This video explains the concept from the ground up using a few examples, and shows the connection between linear transformations and the matrix-vector product.
Notebook is here: http://nbviewer.jupyter.org/github/minireference/noBSLAnotebooks/blob/master/chapter03_exercises.ipynb1995 Technology In Education hearing featuring Seymour Papert and Alan Kay hearing on educationminireference2020-12-28 | A 1995 heating by House Science & Educational Opportunities committees in which Seymour Papert and Alan Kay give interesting opinions on how technology can be used to improve education.Writing a book in two minutesminireference2017-03-02 | Writing a textbook takes a lot of time, but it's totally worth it if you think you have something to teach. This book shows three years worth of writing and edits on the No bullshit guide to linear algebra.
The video was recorded using OBS and the visualization was generated using `gource -s 0.05`, which means 1 day = 0.05 seconds of video.