Mastering Work Intake: From Chaos to Predictable Delivery Chapter 8 shatters myths! Once upon a time in a land far, far away, I believed a few of these myths. Ok, it was just about five years ago that I was dissuaded from the last of my misbeliefs. I believe that many of my misconceptions are founded in the collision of words between classical statistics and words Shewhart used for Process Behavior Charts (PBC).
(more…)February 10, 2024
Re-read Saturday, Actionable Agile Volume II, Week 9, Chapter 8, Myths and Other Considerations
Posted by tcagley under Agile, Measurement, Re-read Saturday | Tags: Measurement, Re-read Saturday, Statistics, Vacanti |Leave a Comment
January 20, 2024
Re-read Saturday, Actionable Agile Volume II, Week 6, Chapter 5 – How Much Data?
Posted by tcagley under Agile, Re-read Saturday, Software Measurement | Tags: Actionable Agile, COVID-19, Daniel Vacanti, Data, Data Analytics, Re-read Saturday, science, Statistics |Leave a Comment
The question of how much data is required to determine what is happening in a system is a perennial bugaboo. Those predisposed to acting tend to think less is more, while those with more reticence sometimes wait forever to make a decision. The question of how much data is needed is more than just a footnote in flow data.
(more…)August 19, 2021
Base Rate Fallacy
Posted by tcagley under Cognitive Bias | Tags: Cognitive Bias, Re-read Saturday, Statistics |Leave a Comment
I took a lot of statistics, quantitative analysis, and math courses in university. I think it was a function of going to three schools during every available semester and building up a boatload of credits before LSU gave me a diploma and made me leave the state. I still remember the day I learned partial differential equations (I finally could understand the footnotes in my economics texts). With all of that, I was not exposed to the idea of a base rate fallacy (known also as base rate bias) until several years later when I was working in the garment industry. Twice this week I have run into scenarios that are examples of base rate fallacies which suggest that many people either don’t understand the concept or are blinded by raw numbers (a shiny object phenomenon).
(more…)August 23, 2018
Monte Carlo: The Assumptions
Posted by tcagley under Agile, Management | Tags: Decision Making, Monte Carlo, Statistics |[2] Comments
Monte Carlo analysis provides a way to handle answering questions with significant uncertainty in the inputs that influence the outcome of the work so you can have the difficult “when, what, and how much” type conversations with sponsors, stakeholders, and marketing people. That definition is an explicit admission that almost ALL of the hard questions asked about projects cannot be answered using simple a + b = c formulas or arguments. This leads us to use tools like Monte Carlo analysis. There are four common assumptions often overlooked or misunderstood when using Monte Carlo methods. (more…)
August 21, 2018
Monte Carlo Analysis – A Brief Rationale For Use In Agile
Posted by tcagley under Agile | Tags: Agile, planning, Statistics |[2] Comments
One of the most often used saying in agile is that yesterday’s weather is a good predictor of tomorrow’s performance. I have lived in Louisiana where if you blink the weather will change. I currently live near Cleveland (and I like it), and in 2014 the temperature went from 39 F to -11 F in less than 24 hours. I went running on both days; they were very different. Even if I grant that yesterday can be an important indicator of performance tomorrow, a sample size of one does not capture the degree of variability that might be present in the environment. Why does anyone care about variability in performance? As suggested in Agile Metrics: An Interlude, leaders have not stopped asking what they can get, when they can get it and how much it will cost type questions. Even if they don’t ask all of those questions there will be questions about budgets. These are not evil, unagile people; they are business people that need to plan things like cash flows and making payroll. Answering when they can deliver product to the market or when a change to the HR portal will be made are important questions. Just relying on yesterday’s weather is not always sufficient and there is no Oracle of Delphi that provides a single, unambiguous answer to any of those questions. The answers are always a range. In most circumstances, each possible outcome is more or less probable than the next. Uncertainty makes it difficult to have a conversation about when, what and how much. Monte Carlo analysis provides a way to handle answering questions with significant uncertainty in the inputs that influence the outcome of the work so you can have the difficult when, what and how much type conversations. (more…)
January 13, 2018
Actionable Agile Metrics for Predictability by Daniel S. Vacanti, Re-read Saturday Week 12: Cycle Time Histograms
Posted by tcagley under Re-read Saturday | Tags: Agile, Histrogram, Re-read, Statistics, Vacanti |[21] Comments
Chapter 10A of Daniel S. Vacanti’s Actionable Agile Metrics for Predictability: An Introduction (buy a copy today) is a very short chapter (I should have planned to include this in chapter 10B, but hindsight is 20/20) covering a discussion of histograms but given the time and space we can spend additional time with an example. The chapter is titled Cycle Time Histograms. (more…)
November 29, 2016
Are Vanity Metrics Statistically Valid?
Posted by tcagley under Measurement | Tags: Statistics, Twitter, Vanity Metrics |Leave a Comment
Over the last two weeks, we published three articles on vanity metrics:
Vanity Metrics in Software Organizations
Vanity Metrics Have a Downside!
One of those articles elicited an interesting discussion on Twitter. The discussion was predominately between @EtharUK (Ethar Alali) and @GregerWikstrand. The discussion started by using the blog entry from 4 Big Myths of Profile Pictures from OKCupid to illustrate vanity metrics, and then shifted to a discussion of whether vanity metrics can be recognized based on statistical validity. The nice thing about Twitter is that responses are forced to be succinct. See the whole conversation here. (more…)
February 27, 2016
How To Measure Anything, Chapter 10: Bayes: Adding To What You Know Now
Posted by tcagley under Re-read Saturday | Tags: Bayes, Measurement, Re-read, Re-read Saturday, Statistics |[10] Comments
Chapter 10 of How to Measure Anything, Finding the Value of “Intangibles in Business” Third Edition is titled, Bayes: Adding to What You Know Now. Here is a summary of the chapter in a few bullet points:
- Prior knowledge influences how we process new information.
- Bayesian statistics help us move from what we know to what we don’t know.
- We are all Bayesian to some extent, but maybe not enough.
- Many myths about using information are just plain wrong, and Bayes proves it.