Tag: education

How most statistical tests are linear models

Jonas Kristoffer Lindeløv wrote a great visual explanation of how the most common statistical tests (t-test, ANOVA, ANCOVA, etc) are all linear models in the back-end.

Jonas’ original blog uses R programming to visually show how the tests work, what the linear models look like, and how different approaches result in the same statistics.

George Ho later remade a Python programming version of the same visual explanation.

If I was thought statistics and methodology this way, I sure would have struggled less! Have a look yourself: https://lindeloev.github.io/tests-as-linear/

A free, self-taught education in Computer Science!

The Open Source Society University offers a complete education in computer science using online materials.

They offer a proper introduction to the fundamental concepts for all computing disciplines. Evyerthing form algorithms, logic, and machine learning, up to databases, full stack web development, and graphics is covered. Moreover, you will acquire skills in a variety of languages, including Python, Java, C, C++, Scala, JavaScript, and many more.

According to their GitHub page, the curriculum is suited for people with the discipline, will, and good habits to obtain this education largely on their own, but who’d still like support from a worldwide community of fellow learners.

Curriculum

Intro CS: for students to try out CS and see if it’s right for them
Core CS: corresponds roughly to the first three years of a computer science curriculum, taking classes that all majors would be required to take
Advanced CS: corresponds roughly to the final year of a computer science curriculum, taking electives according to the student’s interests
Final Project: a project for students to validate, consolidate, and display their knowledge, to be evaluated by their peers worldwide
Pro CS: graduate-level specializations students can elect to take after completing the above curriculum if they want to maximize their chances of getting a good job

It is possible to finish Core CS within about 2 years if you plan carefully and devote roughly 18-22 hours/week to your studies. Courses in Core CS should be taken linearly if possible, but since a perfectly linear progression is rarely possible, each class’s prerequisites are specified so that you can design a logical but non-linear progression based on the class schedules and your own life plans.

Links to the contents

Links to the curriculum (v8.0.0)

Finland’s free online AI crash course

Finland developed a crash course on AI to educate its citizens. The course was arguably a great local success, with over 50 thousand Fins taking the course (1% of the population).

Now, as a gift to the European Union, Finland has opened up the course for the rest of Europe and the world to enjoy.

All pictures are screenshots taken from the website

The course is even being translated into several local languages. At the time of writing, five Northern European languages are already supported, but additional translation efforts are still in progress.

Elements of AI takes six weeks and functions as a crash course and beginner introduction to the field of AI:

Machine Learning and AI courses at Google

Google has announced to provide open access to its artificial intelligence and machine learning courses. On their overview page, you will find many educational resources from machine learning experts at Google. They announced to share AI and machine learning lessons, tutorials and hands-on exercises for people at all experience levels. Simply filter through the resources and start learning, building and problem-solving.

For instance, up your game straight away with this 15-hour Machine Learning crash course. Zuri Kemp – who leads Google’s machine learning education program – said that over 18,000 Googlers have already enrolled in the course. Designed by the engineering education team, the courses explores loss functions and gradient descent and teached you to build your own neural network in Tensorflow.

Online Resource: Efficient R Programming

Public Service Motivation is a theorized attribute of government and non-governmental organization employment that explains why individuals have a desire to serve the public and link their personal actions with the overall public interest (Wikipedia, 2017). Academics are often said to score highly on this public service motivation and I can’t but admire those that share their knowledge freely with the public.

Colin Gillespie and Robin Lovelace are perfect examples of altruistic contributors to society. Their latest book – Efficient R Programming – is a definite recommendation for anybody who wants to power-up their R code, beginner or more advanced programmer. On top of this, the authors provide the digital version free-of-charge!

Time Series Analysis 101

A time series can be considered an ordered sequence of values of a variable at equally spaced time intervals. To model such data, one can use time series analysis (TSA). TSA accounts for the fact that data points taken over time may have an internal structure (such as autocorrelation, trend, or seasonal variation) that should be accounted for.

TSA has several purposes:

Descriptive: Identify patterns in correlated data, such as trends and seasonal variations.
Explanation: These patterns may help in obtaining an understanding of the underlying forces and structure that produced the data.
Forecasting: In modelling the data, one may obtain accurate predictions of future (short-term) trends.
Intervention analysis: One can examine how (single) events have influenced the time series.
Quality control: Deviations on the time series may indicate problems in the process reflected by the data.

TSA has many applications, including:

Economic Forecasting
Sales Forecasting
Budgetary Analysis
Stock Market Analysis
Yield Projections
Process and Quality Control
Inventory Studies
Workload Projections
Utility Studies
Census Analysis
Strategic Workforce Planning

AlgoBeans has a nice tutorial on implementing a simple TS model in Python. They explain and demonstrate how to deconstruct a time series into daily, weekly, monthly, and yearly trends, how to create a forecasting model, and how to validate such a model.

Analytics Vidhya hosts a more comprehensive tutorial on TSA in R. They elaborate on the concepts of a random walk and stationarity, and compare autoregressive and moving average models. They also provide some insight into the metrics one can use to assess TS models. This web-tutorial runs through TSA in R as well, showing how to perform seasonal adjustments on the data. Although the datasets they use have limited practical value (for businesses), the stepwise introduction of the different models and their modelling steps may come in handy for beginners. Finally, business-science.io has three amazing posts on how to implement time series in R following the tidyverse principles using the tidyquant package (Part 1; Part 2; Part 3; Part 4).