IT

Ask E.T.: ET textbook, Data Analysis for Politics and Policy: PDF files now available:

The 179-page book is for courses in applied statistics, particularly for policy making and the social sciences. It deals with making causal inferences from statistical evidence, research designs, predictions and projections, linear and multiple regression. All the examples are real, involving serious questions (no regressions of height on weight that are found in some statistics texts). The technical material is at the level of one or two classes in college math. There is one somewhat more technical part, on logarithmic scale transformations and their interpretation in regression and in graphics. The book was written very much under the influence of Frederick Mosteller, John Tukey, and my professor of statistics at Stanford, Lincoln Moses.

Ask E.T.: Executive decision support systems:

(3) For information displays for management, avoid heavy-breathing metaphors such as the mission control center, the strategic air command, the cockpit, the dashboard, or Star Trek. As Peter Drucker once said, good management is boring. If you want excitement, don’t go to a good management information system.

Ask E.T.: Sparklines: theory and practice:

Here are a few pages from the 18-page chapter on sparklines in Beautiful Evidence (2006).

Mariano Belinky’s Sparkline work

Ask E.T.: Excessively hierarchical organization of information:

Excessively hierarchical organization of information is sometimes explained by Conway’s Law: “Any organization which designs a system . . . will inevitably produce a design whose structure is a copy of the organization’s communication structure.” So user guides represent Conway’s Law squared, a system for understanding a system; a PP user’s guide, the Law cubed.

Why Emacs Always Wins in the End | Compiler from Wired.com:

Emacs always wins – even if it does do text coloring in Leopard.

Typical Programmer – Why Programmers Don’t Like Relational Databases:

Complaining about relational databases is a staple theme of programmer blogs. Why are so many programmers irritated and frustrated with relational databases? Why do the perceived intricacies of SQL and the “object-relational impedance mismatch” launch so many rants? Why are DBAs more hated than managers? I have some ideas.

Inter-Sections » Blog Archive » How to recognise a good programmer

t’s not as easy as it sounds. CV experience is only of limited use here, because great programmers don’t always have the “official” experience to demonstrate that they’re great. In fact, a lot of that CV experience can be misleading. Yet there are a number of subtle cues that you can get, even from the CV, to figure out whether someone’s a great programmer.

Amazon’s Dynamo – All Things Distributed

Dynamo: Amazon’s Highly Available Key-value Store

Giuseppe DeCandia, Deniz Hastorun, Madan Jampani, Gunavardhan Kakulapati, Avinash Lakshman, Alex Pilchin, Swaminathan Sivasubramanian, Peter Vosshall and Werner Vogels

Amazon.com

Abstract

Reliability at massive scale is one of the biggest challenges we face at Amazon.com, one of the largest e-commerce operations in the world; even the slightest outage has significant financial consequences and impacts customer trust. The Amazon.com platform, which provides services for many web sites worldwide, is implemented on top of an infrastructure of tens of thousands of servers and network components located in many datacenters around the world. At this scale, small and large components fail continuously and the way persistent state is managed in the face of these failures drives the reliability and scalability of the software systems.

This paper presents the design and implementation of Dynamo, a highly available key-value storage system that some of Amazon’s core services use to provide an “always-on” experience.  To achieve this level of availability, Dynamo sacrifices consistency under certain failure scenarios. It makes extensive use of object versioning and application-assisted conflict resolution in a manner that provides a novel interface for developers to use.